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What Is CMMRD?

CMMRD, like Lynch Syndrome, is a genetic condition that makes it more likely for a person to get certain types of cancer, except this time it occurs when a child has inherited mutated genes from both parents, and the cancer risk is even higher. PMS2 is the most commonly affected gene in CMMRD.

To illustrate this: my mum has one “good” copy of the gene and one bad copy, so I could have inherited her good gene or her bad gene. And the same goes for my dad. My sister inherited both of their good copies, and therefore doesn’t have Lynch Syndrome or CMMRD, and neither do her children. Whereas I inherited both of their bad genes and therefore have CMMRD. We believe my brother, who passed away many years ago, also had Lynch Syndrome or CMMRD.

As many as 1 in every 300 people may have Lynch Syndrome, while the odds of having CMMRD are one in a million – or 0.0001%. 

What Is CMMRD?

Lynch Syndrome and the Challenge of Getting a Diagnosis

Lynch Syndrome often goes unnoticed in the general population. This is because many individuals affected may not have a family history of cancer or may show unusual symptoms, making it hard to spot without genetic testing.

We need doctors and healthcare teams to know more about Lynch Syndrome, provide more accessible ways for people to get genetic testing, and offer simpler ways to find out if someone might have Lynch Syndrome and if they’re at risk.

Lynch Syndrome and the Challenge of Getting a Diagnosis

Important information about Womb Cancer

Lynch syndrome may affect up to 175,000 people in the UK and is linked to 3% of cases of womb cancer.

To develop Lynch syndrome you need to have one parent that carries the gene. Someone diagnosed with Lynch syndrome has up to 60% chance of developing womb cancer in their lifetime.

Lynch syndrome is also associated with an increased risk of bowel cancer.

Those diagnosed with Lynch syndrome undergo regular tests to check for bowel cancer and womb cancer, many will be offered a hysterectomy (operation to remove the womb) to prevent womb cancer once they feel their family is complete.

Lynch syndrome is often diagnosed when a strong family history of bowel or womb cancer is noted. If you feel this may apply to you, please speak to your doctor about being referred to a genetics service.

Information on Womb Cancer

Updates in gynaecologic care for individuals with lynch syndrome

As the landscape of gynaecologic cancer treatment shifts towards treatment based on molecular classification of tumours, knowledge of targeted therapies well-suited for mismatch repair deficient Lynch tumours will be crucial.

 Identifying barriers and improving access to risk reduction measures is another future direction in the study of Lynch syndrome, and perhaps the greatest frontier is determining whether Lynch-associated endometrial and ovarian tumors should be treated differently than sporadic endometrial and ovarian tumors.

https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2023.1127683/full

Cancer Trials -Questions for your doctor

If you would like to know more about whether there is a cancer trial suitable for you,  the first thing you do is to talk to your doctor and/or the cancer trials research team in your hospital.

Questions for your doctor

Genomics Toolkit: Gynae-Macmillan Cancer Support

The Macmillan Genomics Toolkit is designed to guide healthcare professionals to multiple education resources, pathway guidelines, clinical documents, patient support information and case studies to demonstrate the ‘Gold Standard’ of care once genomics has been embedded into practice. It has been developed in collaboration with expert healthcare professionals and the NHS England National Genomics Education team.

https://www.macmillan.org.uk/healthcare-professionals/innovation-in-cancer-care/genomics-toolkit/gynae

Preventing Lynch Syndrome Cancers: Study Suggests Immunotherapy Could Work

Lynch syndrome is linked to cancers of the gastrointestinal tract, including colon cancer, rectal cancer, and stomach (gastric) cancer, and cancers of the small intestine.

It also increases the risk of uterine (endometrial) cancer, ovarian cancer, and some cancers of the upper urinary tract.

People with Lynch syndrome have such a high risk of developing cancer because they carry a gene mutation that prevents their cells from being able to repair genetic damage. This leads to a condition called DNA mismatch repair deficiency (MMRd).

These MMRd cancers have a lot of mutations, which makes them visible to the immune system. Therefore, drugs that enlist the immune system to fight cancer cells are particularly effective. Past research from Dr. Diaz and others found that tumors with MMRd are more likely to respond to checkpoint inhibitors. Thanks to that discovery, these drugs are now widely used to treat patients whose tumors have MMRd, including those whose cancers are due to Lynch syndrome.

https://www.mskcc.org/news/preventing-lynch-syndrome-cancers-new-study-suggests-immunotherapy-could-work

In Lynch syndrome, high-quality colonoscopy surveillance is of utmost importance for Colorectal Cancer prevention

Background & aims: Colonoscopy reduces colorectal cancer incidence and mortality in Lynch syndrome carriers. However, a high incidence of postcolonoscopy CRC(PCCRC) has been reported. Colonoscopy is highly dependent on endoscopist skill and is subject to quality variability. We aimed to evaluate the impact of key colonoscopy quality indicators on adenoma detection and prevention of PCCRC in LS.

Conclusions: Complete colonoscopies with adequate bowel preparation and chromoendoscopy use are associated with improved adenoma detection, while surveillance intervals of less than 3 years are associated with a reduction of PCCRC incidence. In LS, high-quality colonoscopy surveillance is of utmost importance for CRC prevention.

https://pubmed.ncbi.nlm.nih.gov/33157315