Bowel Cancer UK is campaigning to improve the identification and management of people with Lynch syndrome.
They’ve put together a 15 minute survey to give people the chance, anonymously, to share their experience of being diagnosed, and managed for Lynch syndrome.
Your experiences will help Bowel Cancer UK to continue to campaign to improve the diagnosis and management of Lynch syndrome.
Please share the survey with your family and friends who also have Lynch syndrome.
Mismatch repair genes have long been a source of fascination to basic biologists. Normally, these genes serve to fix the small glitches that occur when DNA is copied as cells divide. Most of the original work was done in bacteria, with no expectation of medical relevance. But, as often happens, basic science studies can provide a profoundly important foundation for advances in human health. The relevance of mismatch repair to cancer was dramatically revealed in 1993, when teams led by Bert Vogelstein of Johns Hopkins School of Medicine, Baltimore, and Richard Kolodner, then of Harvard Medical School, Boston, discovered that mutations in human mismatch repair genes play a key role in the development of certain forms of colorectal cancer.
Mismatch repair deficiency is found in 15% to 20% of sporadic (noninherited) colorectal cancers and in nearly all colorectal cancers associated with Lynch syndrome, which constitute up to 5% of all colorectal cancers. Mismatch repair deficiency is also found in other tumor types including stomach, small bowel, endometrial, prostate, and ovarian cancer. Testing for mismatch repair deficiency is widely available and could enable identification of a larger population of patients who might benefit from pembrolizumab and other PD-1 drugs.
That discovery has led to the ability to identify individuals who have inherited misspellings in these mismatch repair genes and are at high risk for colorectal cancer, providing an opportunity to personalize screening by starting colonoscopy at a very early age and, thereby, saving many lives. But now a new consequence of this work has appeared. Vogelstein and his colleagues report that mismatch repair research may help fight cancer in a way that few would have foreseen two decades ago: predicting which cancer patients are most likely to respond to a new class of immunotherapy drugs, called anti-programmed death 1 (PD-1) inhibitors.
In a small, proof-of-principle study recently published in The New England Journal of Medicine and presented at the American Society of Clinical Oncology’s annual meeting, the Johns Hopkins researchers reported that they could predict the benefit of an anti-PD-1 inhibitor called pembrolizumab (Keytruda®) by scanning patients’ tumor samples for defects in mismatch repair. Regardless of their type of cancer, patients whose tumors were mismatch repair deficient were more likely to respond to the immune-boosting, anti-PD-1 drug than those with tumors proficient in mismatch repair. In fact, the worse the tumor cells were at repairing DNA, the better the patients fared on anti-PD-1 therapy!
This may all sound counterintuitive. However, researchers say it supports the hypothesis that immunotherapy may be most effective against tumors with many mutations. (In the new study, the tumor cells deficient in mismatch repair contained more than 20 times as many mutations, on average, than tumor cells proficient in mismatch repair.) The idea is that the greater the number of DNA glitches in a tumor cell, the more abnormal proteins it will produce—and the more abnormal proteins that are generated, the greater the odds that the body’s immune cells will regard the tumor cells as “foreign” and target them for destruction.
To test this hypothesis, Vogelstein, Luis Diaz, Jr., and their colleagues initiated a phase II clinical trial to evaluate pembrolizumab, which is already approved by the Food and Drug Administration for treating certain patients with melanoma, in 32 patients with advanced colorectal cancer. Some of the patients had tumors that were mismatch repair deficient; others had tumors proficient in mismatch repair. The researchers also enrolled nine people with cancers of the pancreas/bile duct, uterus, small bowel, and stomach that tested positive for mismatch repair defects. The patients, all of whom had not responded to at least one previous cancer treatment, were administered the anti-PD-1 drug intravenously every two weeks.
After at least 20 weeks of anti-PD-1 therapy, the researchers found that colorectal tumors shrank in about 40 percent of patients in the mismatch repair deficient group, compared to none in the mismatch repair proficient group. Furthermore, 78 percent of the mismatch repair deficient group was free of tumor progression at 20 weeks, compared to 11 percent of the mismatch repair proficient group.
According to the researchers, the average overall survival time for colorectal patients in the mismatch repair deficient group has not yet been reached because some are still responding well to anti-PD-1 therapy, more than a year after the study started. In contrast, average overall survival among patients in the mismatch proficient group was reported to be only 5 months.
As for the patients with other types of mismatch repair deficient cancer, their tumors shrank at rates similar to those seen in mismatch repair deficient colorectal cancer. However, such patients tended to respond faster to anti-PD-1 therapy than the colorectal cancer patients. And, unlike the colorectal group, a complete remission of cancer was observed in one patient—a woman with uterine cancer. No treatment-related deaths occurred in the study, with the most serious adverse reaction being pneumonitis (inflammation of the lung) in one patient.
The team will continue to follow these patients and enroll more volunteers to see if their findings hold up in a larger study. They also hope to start similar trials for some of the many other types of cancer, such as prostate and ovarian, known to contain mismatch repair deficiencies in a small percentage of tumors. Another area of scientific exploration is whether patients whose tumors contain other types of DNA repair deficiencies, such as those caused by POLD, POLE, and MYH mutations, might also benefit from anti-PD-1 therapy.
This research is just one of many outstanding examples of how decades of research by NIH-supported basic, translational, and clinical scientists continue to move us towards the era of precision medicine. NIH’s National Cancer Institute recently took a major step in that direction by announcing the Molecular Analysis for Therapy Choice, or NCI-MATCH trial. This pioneering clinical study will precisely match patients from as many as 2,400 sites across the country to one of more than 20 targeted drugs or drug combinations based on the particular molecular abnormalities of their individual tumors . With this and many other new efforts envisioned by the Precision Medicine Initiative, it seems as though a future of more precise, individualized approaches to the diagnosis, treatment, and prevention of cancer and many other diseases is now within sight.
There has been quite a backlash to the recent news that many cancers are due to “bad luck” of random mutations, which was proclaimed in headlines around the world, and based on a report published in the January 2 issue of Science.
The International Agency for Research on Cancer (IARC), the World Health Organization’s specialized cancer agency, put out a press release to say that it “strongly disagrees with the conclusion,” and warning that the message could harm cancer research and public health.
“We already knew that for an individual to develop a certain cancer there is an element of chance, yet this has little to say about the level of cancer risk in a population,” explained IARC director Christopher Wild, PhD. “Concluding that ‘bad luck’ is the major cause of cancer would be misleading and may detract from efforts to identify the causes of the disease and effectively prevent it.”
As previously reported by Medscape Medical News, the researchers, from Johns Hopkins University in Baltimore, reported that in about two-thirds (22 of the 31) of cancer tissue types they had investigated, the cancer could be largely explained by the bad luck of random mutations that arise during DNA replication in normal noncancerous stem cells.
However, many of the news stories reported a distorting simplification of the findings, and stated that two-thirds of all cancers are due to bad luck.
There has been fierce criticism of the way that the media reported the story, but an expert argues that journalists were misled.
The Science report was accomapnied by an editorial entitled “The Bad Luck of Cancer,” and the subheading added: “Analysis suggests most cases can’t be prevented.”
But the data do not support either of these ideas, noted George Davey-Smith, MD, a clinical epidemiologist at Bristol University, United Kingdom, in a BBC News report. He also noted that “in the press release [from the Johns Hopkins School of Medicine], the authors say they’ve come up with a method to quantify the contribution of these stochastic or chance factors, which their method doesn’t,” he adds.
“It’s both in the journal and in the press release so it’s just not fair to attribute the mis-reporting of this to journalists,” Dr Davey-Smith commented.
In reaction to the huge media uptake of the story, the study authors issued further comments in a Johns Hopkins University statement, which also included the press release that had been “ammended for clarity.” The public relations officer for Johns Hopkins University, Vanessa Wasta, MBA, noted that the press release was updated to change reference from “incidence” to “risk” as a clarification in the first paragraph, but pointed out to Medscape Medical News that the original news release contained no reference to “cases” or “all” cancers, but referred to “risk” many times.
Science ran a follow-up piece, entitled “A Science Reporter’s Reflections on a Controversial Story,” in which the author returned to the researchers for clarification. “We did not claim that two-thirds of cancer cases are due to bad luck,” said lead author Christian Tomasetti, PhD, an assistant professor of oncology at the Johns Hopkins School of Medicine and the Bloomberg School of Public Health. What the study argued, he explained, was that two-thirds of the variation in cancer rates in different tissues could be explained by random bad luck.
Dr Tomasetti also said that many scientists and statisticians had also needed clarification, and that the team is now working on a technical report with additional details.
Bowel Cancer UK and clinical experts are urging all hospitals across the UK to implement Lynch syndrome testing at diagnosis for everyone with bowel cancer under the age of 50. Lynch syndrome is an inherited condition which causes over 1,000 cases of bowel cancer in the UK every year, many of them in people under the age of 50. However, fewer than 5% of people with Lynch syndrome in the UK have been diagnosed.
Testing everyone with bowel cancer under the age of 50 at diagnosis for Lynch syndrome will help identify family members who may carry Lynch syndrome and be at risk of bowel cancer. It has been shown to be cost effective for the NHS, and is recommended by the Royal College of Pathologists and British Society of Gastroenterologists. It is also a key recommendation in our Never Too Young campaign.
People with Lynch syndrome should then access regular surveillance screening, which can detect bowel cancer in the early stages and has been shown to reduce mortaility from bowel cancer by 72%.
Despite this, testing and surveillance screening are patchy across the UK. A letter in the Daily Telegraph (13 November 2014) from eight leading clinical experts supports our call for all hospitals to implement Lynch syndrome testing at diagnosis for people with bowel cancer under the age of 50.
The letter and signatories are as follows:
There are more than 1,000 cases of bowel cancer a year that are attributable to Lynch syndrome (LS), many under the age of 50. LS is an inherited condition that predisposes individuals to bowel and other cancers, with a lifetime risk of around 70 per cent. Yet in the UK we have identified fewer than 5 per cent of families with LS. The family of Stephen Sutton, who was diagnosed with bowel cancer and whose father has LS, was one of them. It is a consistently under-recognised, under-diagnosed and inadequately treated condition.
Both the Royal College of Pathologists and the British Society of Gastroenterology recommend testing everyone with bowel cancer under the age of 50 at diagnosis to help us to identify family members who may carry LS and be at risk of bowel cancer. Yet testing is patchy. We urge all hospitals across the UK to implement this guidance.
This testing would mean people at risk could access surveillance programmes for regular colonoscopies, helping detecting bowel cancer early but also preventing it.
Patient groups such as Bowel Cancer UK are in support. A recent NHS study found that LS testing at diagnosis for everyone under 50 with bowel cancer would be cost effective enough to have been approved by NICE. The evidence is overwhelming. We must end this postcode lottery.
Dr Suzy Lishman, President, The Royal College of Pathologists
Professor Malcolm Dunlop MD FRCS FMedSci FRSE, Colon Cancer Genetics Group and Academic Coloproctology, Head of Colon Cancer Genetics, Institute of Genetics & Molecular Medicine
Professor D Gareth Evans MD FRCP, Professor of Clinical Genetics and Cancer Epidemiology and Consultant Geneticist, University of Manchester
Commenting on the letter from clinical experts, Deborah Alsina, CEO of Bowel Cancer UK, said:
“The Royal College of Pathologists recently produced best practice guidelines recommending everyone with bowel cancer under the age of 50 should be tested for Lynch syndrome at diagnosis. Speedy implementation is vital as testing is currently patchy at best and if people are tested at all, it is often after treatment ends. Yet a diagnosis of Lynch syndrome can affect treatment decisions. We are therefore calling for all UK hospitals to implement this guidance swiftly.”
“This will also help to identify the risk to other family members who may also carry Lynch syndrome and who may be at higher risk of developing bowel cancer. Once identified, people at risk, including those diagnosed who have a greater chance of recurring or developing another linked cancer, should have access to surveillance programmes including regular colonoscopies. This will help to ensure bowel cancer is either prevented or detected early.”
Bowel Cancer UK will be writing to all Clinical Commissioning Groups and Health Trusts in the UK asking them if they have implemented systematic Lynch syndrome testing, and we will report back on the responses. In the meantime, please share our infographic on the subject on social media to help raise awareness of the issue.
Venue: St Mark’s Hospital, London
Target Audience: All members of the Colorectal Cancer MDT (nurse specialists, oncologists, gastroenterologists, colorectal surgeons, pathologists), Geneticists, genetics counsellors
Learning Style: Lectures and case discussions
Learning Outcomes: On completion of this course, attendees will:
£150.00 – Consultants
£75.00 – Nurses, Trainees and other Healthcare Professionals
Hayley Hovey was 23 weeks’ pregnant with her first baby when she suddenly woke in the middle of the night with a sharp, shooting pain in her side.
She visited her GP’s out-of-hours service but was reassured to hear her baby’s heartbeat and be told all was well. The pain was probably ‘ligament strain’ caused by the weight of the growing baby. ‘I was ecstatic to be having a baby – I’ve always wanted to be a mum,’ says Hayley, 34. ‘All my scans showed my baby was healthy, so I didn’t think anything more about that pain.’
She now knows it was the first sign there was a grave threat to her baby’s life, and her own. Four weeks later her daughter, Autumn, was born prematurely and later died. Then Hayley was found to have bowel cancer.
Doctors now think Autumn’s death was linked to her mother’s cancer, with a blood clot breaking away from the tumour, damaging Hayley’s placenta and cutting off the food supply to her unborn baby.
However, it took four months after Autumn’s death for Hayley to be diagnosed. The problem was her age – she was ‘too young’ for bowel cancer to be considered.
Hayley, who lives in Fareham, Hants, with her husband Paul, a 35-year-old IT consultant, says: ‘Looking back, I had textbook symptoms – exhaustion, intermittent stomach pains, increasingly bad diarrhoea, blood in my stools and bleeding.
The disease is Britain’s second-biggest cancer killer, claiming 16,000 lives a year. The number of under-50s diagnosed has been gradually rising – to around 2,100 a year.
But a recent survey by the charity Bowel Cancer UK of patients under 50 found that 42 per cent of the women had visited their GP at least five times before being referred for tests.
Indeed, Hayley, a supply planner for an IT firm, was examined five times by different doctors and midwives, who all missed her symptoms, despite a golf ball-sized lump appearing on her stomach after her pregnancy. By the time she was diagnosed, Hayley had stage three to four cancer, meaning the tumour had broken through her bowel wall.
She had to undergo a seven-hour operation to remove the 6cm growth, followed by six months of chemo and radiotherapy.
But her experience is not uncommon, says Deborah Alsina, chief executive of Bowel Cancer UK: ‘We hear from many younger people who express frustration at not getting a diagnosis and support.’
‘Bowel cancer is often associated with older patients over 50 – but younger people can, and do, regularly get it, as the tragic story of Stephen Sutton recently highlighted,’ adds Kevin Monahan, consultant gastroenterologist at West Middlesex University Hospital, London.
Stephen Sutton, 19, raised more than £3million during his three-year battle against multiple tumours
Stephen Sutton, the 19-year-old fundraiser who died last week from the disease, told the Mail earlier this month of his anger that he was not diagnosed for six months after his symptoms started. This was despite his family history of Lynch syndrome, a genetic condition that raises the risk of bowel cancer.
‘If it had been caught earlier, it could have led to a better prognosis,’ he said. Hayley, too, eventually discovered she had Lynch syndrome.
Bowel cancer is very treatable if detected early – 93 per cent of patients who are found to have a small tumour on the bowel wall live for five years or more. Yet only 9 per cent of cases are diagnosed at this stage – most are diagnosed at stage three. So, the overall five-year survival rate for bowel-cancer patients is just 54 per cent.
Because patients and many doctors assume that young people won’t get bowel cancer, they are particularly likely to have advanced-stage tumours at the time of diagnosis.
Bleeding or blood in faeces
A change in bowel habits lasting more than three weeks
Unexplained weight loss
See bowelcanceruk.org.uk; beatingbowelcancer.org (phone 08450 719 301); and familyhistorybowelcancer.wordpress.com/
Cancer charities are campaigning to improve diagnosis for all ages – they want new diagnostic guidelines for GPs and earlier screening procedures.
Sean Duffy, NHS England’s national clinical director for cancer, says: ‘The UK lags behind much of Europe in terms of survival from bowel cancer. We need to change this, and this includes identifying it better in patients under 50.’
National GP guidelines state only patients aged 60 and over should be automatically referred to hospital for tests if they have one symptom. Patients aged 40 to 60 must exhibit two or more symptoms.
For under 40s, there is often an assumption the symptoms must be something else, says Mark Flannagan, chief executive of the charity Beating Bowel Cancer. ‘We’ve had patients with red-flag symptoms – such as blood in their stools – being told “you’ve got IBS” or “you’re too young to have cancer” by their GPs.’
Four weeks after Hayley’s initial scare, she was unable to feel her baby moving. Tests revealed Autumn had stopped growing, and she had to be delivered by emergency caesarean. After her birth, in July 2011, she was taken to a specialist neo-natal unit at Southampton General Hospital but died in hospital a few weeks later.
Two weeks afterwards, Hayley experienced more shooting pains. With her pregnancy bump gone, there was also a noticeable lump on the side of her waist. Her midwife said it was probably an infection, and Hayley was given antibiotics.
But her health deteriorated rapidly and she had to take six weeks off work with exhaustion, which her GP put down to depression.
Within three months of Autumn’s death, Hayley was suffering from nausea and abdominal pain.
Unable to get a GP’s appointment, she went to A&E but was told the lump was possibly an infection related to her caesarean. Doctors performed a cervical smear test (which was subsequently lost) and sent her home with paracetamol.
Stephen Sutton with his mother Jane whilst Prime Minister David Cameron visited him
‘I got the impression they didn’t take me very seriously,’ she recalls.
Soon after, she was vomiting up to ten times a day, feeling dizzy and weak, passing blood and experiencing chronic diarrhoea. At an emergency GP appointment, she was examined by a different doctor who immediately referred her to hospital; after several days of tests, she was diagnosed with cancer.
Four days before Christmas, Hayley underwent surgery. ‘We thought we’d be enjoying our first Christmas as a family, but instead I was in hospital, grieving for the loss of our little girl and terrified about the future,’ she recalls. ‘My treatment might have been less of an ordeal if my cancer had been picked up sooner. It makes me quite angry to think if I’d been 60, it would have been picked up more quickly.’
But even obvious symptoms are often missed by doctors, says Mr Flannagan. ‘I am not blaming GPs, but we need to not be shy of pointing out where things are going wrong. The default position should be for a GP to rule out cancer, just to be safe.’
‘It can also be problematic if patients don’t have obvious symptoms such as bleeding’, says Dr Monahan. ‘They may instead have vaguer symptoms such as tiredness, unexplained weight loss or abdominal pain, which could be attributed to being symptoms of other conditions such as irritable bowel syndrome or Crohn’s disease.’
Public awareness is also an issue. A survey in March by health insurer AXA PPP found nearly half of men couldn’t name one symptom of bowel cancer.
Indeed, Martin Vickers, 49, had never heard of it before his diagnosis in 2008. ‘I was totally shocked,’ says the father of four, who lives in Burton-on-Trent with wife Andrea, 48. ‘I didn’t know bowel cancer existed. It was hugely traumatic.’
Martin visited his GP five times in nine months with extreme tiredness and loose stools. His symptoms were attributed to stress – his mother had recently died and he has a high-pressure job as head of capital investment for Cambridge and South Staffordshire Water – and then IBS.
Joining friends and family to complete a Guinness Book of Records challenge creating hearts with hands
‘But I knew something wasn’t right,’ says Martin. ‘It was instinctive.’ He was finally diagnosed with stage three bowel cancer in November 2008, after his GP did an internal examination and felt a lump.
Martin underwent three months of chemotherapy and radiotherapy, followed by surgery, another six months of chemotherapy and a second operation. He now has to use a colostomy bag but has been in remission for five years.
Currently, screening is only available to people aged 60-plus. They are sent home tests, which involve sending a stool sample to a lab. But the Department of Health is now looking at a new procedure, bowel scope screening, which involves a partial colonoscopy -examining only the lower bowel.
A major UK trial of 55 to 64 year olds showed that people screened this way were 43 per cent less likely to die from bowel cancer, and 33 per cent less likely to develop it.
This is because the procedure is usually successful at detecting small growths known as polyps, which can become cancerous.
The screening – which would be offered to everyone aged 55 and over – is now being piloted. Campaigners hope it will be made available nationally by 2016.
‘This is a really important development and should make a big difference to bowel cancer outcomes,’ says Dr Monahan, who runs the Family History of Bowel Cancer clinic at West Middlesex University Hospital, specialising in hereditary components of the disease.
It won’t, however, help younger patients such as Hayley. Before her chemotherapy, she and Paul had nine embryos frozen via IVF. However she is worried she may pass on Lynch syndrome, so the couple are considering what to do.
But she says: ‘I am still here, I have a life ahead of me – and I hope my story will help others to be diagnosed in time.’
Our briefing highlights the lack of surveillance screening for younger people at higher risk of bowel cancer.
Genetic factors contribute up to 30% of bowel cancer cases, an estimated 8,000-12,000 cases each year.
Genetic factors mean a strong family history of bowel cancer, or genetic conditions such as familial adenomatous polyposis (FAP) or Lynch syndrome. People with long-term inflammatory bowel disease are also at higher risk.
People in higher risk groups are likely to develop bowel cancer much younger than the general population. Clinical guidance recommends that people in high-risk groups should be in a surveillance screening programme, which is proven to reduce deaths in these groups.
Recent evidence shows that:
Our briefing, “Never too young: Supporting people at higher risk of bowel cancer”, has five recommendations to improve services for people in high risk groups:
Full details of our findings and recommendations are in our full report available here.
Does your family have a history of early onset colon cancer? If so, your family may have Lynch syndrome. Lynch syndrome may also increase one’s chances of developing cancers of the stomach, small intestine, liver, gallbladder ducts, upper urinary tract, kidneys, bladder, pancreas, brain, skin, and if you are a male, the prostate. Women with this syndrome also are at higher risk for developing cancer of the endometrium, ovaries, and breasts. Approximately up to 1,000,000 people in the U.S. have Lynch syndrome and yet only 5% know it. Genetic testing, along with preventative measures, and annual medical screening may help one take steps to minimize risk of illness and death.
In new recommendations published in the , ASCO stated that family history of cancer in first- and second-degree relatives is critical to assessing for familial risk in patients with cancer. ASCO’s recommendations are the first to focus on family history taking specifically in oncology to help determine patients’ personal genetic risk for cancer.
Although the current standard in medical genetics, genetic counseling and research settings is a comprehensive recording of three generations, following a review of all available evidence, ASCO concluded that reported family history is most accurate in close relatives and loses accuracy in more distant relatives.
“Genetic factors are a key component of precision medicine because they can unlock important information that can help an oncologist determine the best course of individualized treatment, “ said ASCO President Clifford A. Hudis, MD, FACP. “An adequate family history is key to identifying those patients whose cancer may be associated with inherited genetic factors.”
For each relative with cancer, ASCO recommends recording type of primary cancer(s), age at diagnosis, lineage (maternal and/or paternal), ethnicity and results of any cancer genetic testing in any relative. Family history information should be recorded at a patient’s initial visit to the oncology provider, and be reassessed if new information about family members diagnosed with cancer becomes available.
Addressing Barriers to Implementation
In a separate analysis of data from ASCO’s Quality Oncology Practice Initiative QOPI®, results showed that of breast and colorectal patients with a first degree family history of cancer, 79.8 percent were documented in their chart and for those with a second degree family history of cancer, 64.6 percent were documented. These results document a greater opportunity for oncologists to maximize the potential of family history taking, and set a baseline for further quality improvement efforts.
To address barriers to implementation, ASCO recommends increasing patient education and awareness on the importance of a family history and the significance of a cancer risk assessment for patients and their family. Cancer.Net, ASCO’s patient website, will offer an article and infographic, as well as a cancer family questionnaire patients can download.
ASCO also notes that the increasing use of electronic health records (EHRs) can help providers overcome challenges to adopting these new recommendations.
ASCO will be providing a comprehensive update of cancer genetics including family history assessment at its annual meeting. For more information about ASCO’s prevention and genetics work, please click here.
Lynch syndrome, familial adenomatous polyposis, and Mut Y homolog (MYH)-associated polyposis are three major known types of inherited colorectal cancer, which accounts for up to 5% of all colon cancer cases. Lynch syndrome is most frequently caused by mutations in the mismatch repair genes MLH1, MSH2, MSH6, and PMS2 and is inherited in an autosomal dominant manner. Familial adenomatous polyposis is manifested as colonic polyposis caused by mutations in the APC gene and is also inherited in an autosomal dominant manner. Finally, MYH-associated polyposis is caused by mutations in the MUTYH gene and is inherited in an autosomal recessive manner but may or may not be associated with polyps. There are variants of both familial adenomatous polyposis (Gardner syndrome—with extracolonic features—and Turcot syndrome, which features medulloblastoma) and Lynch syndrome (Muir–Torre syndrome features sebaceous skin carcinomas, and Turcot syndrome features glioblastomas). Although a clinical diagnosis of familial adenomatous polyposis can be made using colonoscopy, genetic testing is needed to inform at-risk relatives. Because of the overlapping phenotypes between attenuated familial adenomatous polyposis, MYH-associated polyposis, and Lynch syndrome, genetic testing is needed to distinguish among these conditions. This distinction is important, especially for women with Lynch syndrome, who are at increased risk for gynecological cancers. Clinical testing for these genes has progressed rapidly in the past few years with advances in technologies and the lower cost of reagents, especially for sequencing. To assist clinical laboratories in developing and validating testing for this group of inherited colorectal cancers, the American College of Medical Genetics and Genomics has developed the following technical standards and guidelines. An algorithm for testing is also proposed.