Issue 15 | March 2018
March is Colorectal Cancer Awareness Month
Welcome back to another issue of myStrand! March is Colorectal Cancer Awareness Month and we would like to use the occasion to highlight symptoms, risk factors, and prevention of the third most common cancer worldwide. Plus, we bring you another story of courage from a family affected by one of the hereditary forms of colorectal cancer
The myStrand Team!
Colorectal Cancer – Symptoms, Risk Factors, and Prevention
What is Colorectal Cancer?
The term Colorectal Cancer encompasses both cancers that originate in the colon or large intestine and the rectum. Colorectal cancer typically starts out with benign (harmless) growths called adenomatous polyps. As time passes, these polyps sometimes develop into colon cancer. Because polyps cause very few mild symptoms, or sometimes no symptoms even, they often go undetected. However, polyps can easily be detected through a medical procedure called colonoscopy, which makes a great screening tool for this cancer – but more on this later.
What are the symptoms of Colorectal Cancer?
Common signs and symptoms of colon cancer are:
It is important to point out that the vast majority of colorectal cancer cases develop after the age of 50. However, there are certain risk factors that can bring down the age of onset to below 40 years, which include many lifestyle habits, and, like diabetes, the incidence of colorectal cancer is increasing rapidly in India primarily to our changing habits. Diets that are rich in meats, processed fats, processed carbohydrates and low on dietary fiber can increase the risk for colorectal cancer.
What increases Colorectal Cancer risk?
Like for any other cancer, there are many risk factors that can contribute to an increase in colorectal cancer risk. The primary risk factor is age with almost 90% of cases occurring in people aged 50 years or older.
The primary cause for colorectal cancer is attributed to genetics – genetic mutations occur naturally and quite randomly in individual cells as our bodies age and there is little we can do about that. However, sometimes, a genetic change is present in all our cells because it occurred in a germline cell of an ancestor and was then passed on through generations of families. There are many such germline mutations that we know about today that increase the risk for breast cancer, like BRCA1 and BRCA2, but we also know about a few that significantly increase the risk for getting colorectal cancer: A syndrome called familial adnomatous polyposis (FAP) is caused by mutations in the APC gene, while Lynch Syndrome is caused by mutations in the EPCAM, MLH1, MSH2, MSH6, PMS2 genes.
Your own personal medical history also plays a role. If you have been diagnosed with colorectal cancer or polyps in the past, it is important to be vigilant and attend regular screening appointments as indicated by your doctor. Also, if you are suffering from one of the inflammatory bowel diseases (Crohn’s or Ulcerative Colitis) you are at an increased risk for developing colorectal cancer!
However, more recent observations and studies into colorectal cancer incidence have also revealed that lifestyle and diet play an important role in the development of colorectal cancer. Some studies even estimate that 50% of colorectal cancer cases can be attributed to dietary factors, while others reckon that up to 75% of colorectal cancer cases could be prevented if we all followed a healthy diet and exercised enough, not to mention avoiding alcohol and not smoking.
How can we prevent Colorectal Cancer?
Colorectal Cancer is one of the cancers that many consider curable, provided it is caught in the early stages. Hence, the key to prevent colorectal cancer disrupting your life is:
- Have you already been diagnosed with colorectal cancer or polyps?
- Are you suffering from Crohn’s Disease or Ulcerative Colitis?
- Do you have diabetes? Diabetes and insulin resistance are known risk factors for colorectal cancer.
- Do you have a family history of colorectal cancers? If yes, get in touch with one of our genetic counselors to learn more about the hereditary forms of colorectal cancer and understand whether you might be at an increased risk. A genetic test will also help confirm or rule out your hereditary status if there is a strong family history.
So make the pledge to live a healthy life! Colorectal cancer need not be another epidemic sweeping India. It is still a disease of Western countries with over 50% diagnosed there. But it claims far too many lives in less developed countries because of poorer healthcare systems and lack of awareness. You’ve just taken care of the awareness part by reading this article – don’t wait for the medical system to fail you!
Disclaimer: The information provided in this article is in no way intended to replace expert medical advice. Always discuss any concerns with your doctor.
There are no time machines but…
Cancer, including colon and colorectal cancer, is an ever more present disease in India with the number of cases increasing over the last few years. A key factor in treating and curing cancer is early diagnosis! Unfortunately, we cannot go back in time to undo a cancer diagnosis, but what many don’t realize is that there are regular screening measures and preventive options available today to everyone, but especially so in cases where the risk of disease is higher because of family history. This type of cancer is known as hereditary cancer and in the case of colorectal cancer and other associated cancers, it is also known as Lynch Syndrome. For example, if a mother had endometrial cancer and the grandfather had
colon cancer, a daughter or son is at a much higher risk of getting those cancers than the average person. A genetic counsellor is trained to look at a person’s family history and estimate that risk, and these days there are even tests that can be recommended to affected families to ascertain whether an increased risk is indeed present or not in the next generation. Visit our dedicated webpage to learn more about hereditary cancer: www.strandls.com/stayaheadofcancer
Choosing to Know
About Lynch Syndrome
Lynch Syndrome is a hereditary cancer syndrome that is primarily known for increasing a person’s lifetime risk of colorectal cancer with an earlier age of onset than the average age of over 50 years. However, it also increases the risk of other cancers including endometrial and ovarian cancers in women and gastric, duodenal, urothelial, and central nervous system cancer in both women and men. The syndrome is caused by germline mutations in the EPCAM, MLH1, MSH2, MSH6, PMS2 genes that can be passed down through families with a 50% chance of inheritance.
A cancer diagnosis
A little while ago Sohanlal Shah (not his real name of course to protect the patient’s privacy) was referred to Strand for genetic testing by his oncologist. He had been diagnosed with colorectal cancer at the age of 52 despite leading a reasonably healthy life. However, when the oncologist started asking about his family history of cancer, a rather complex picture of various cancers spread across many branches of his family tree emerged. Suspecting that genetics might have a role to play in this cancer case, the oncologist suggested a detailed counselling session with a genetic counsellor.
Genetic counselling and family trees
Genetic counselors are specially trained to understand inheritance patterns of genes and deduct from often complex family histories whether a genetic mutation could be to blame for the occurrence of a particular disease, in this case colorectal and other cancers. The more information you have about your medical family history the better, and before you know it, thanks to the genetic counsellor’s expertise and specialized software, a detailed family tree (also known as a pedigree) emerges (see Figure 1). In Mr. Shah’s case, the family history spanning three generations revealed a total of eight cases of colorectal cancer (in addition to his own diagnosis), two cases of endometrial cancer and one case of duodenal cancer.
The test was positive
Based on such a high incidence of these three types of cancer in Mr. Shah’s family, the genetic counsellor suspected a case of Lynch Syndrome in the family and recommended a genetic test to look for genetic mutations that would confirm her suspicion. Mr. Shah agreed to take the Strand Germline Cancer Test and was found positive for a likely pathogenic mutation in the MLH1 gene, indicative of Lynch Syndrome. Since these types of mutations are inherited and can be passed on to the next generation, the genetic counsellor informed Mr. Shah that there is a 50% chance that his son Sahil might have inherited the same mutation.
What about the extended family?
Thankfully, Sahil was not affected at this point of time, but knowing if he carried the same mutation as his father would allow him to take preventive measures. Getting tested was now also much more straightforward and economical, because all that was required was to establish whether the same mutation that was identified in his father’s genome was also present in Sahil’s genome. This process is called mutation-specific testing (MST) and is routinely recommended to family members of patients that were found positive for a hereditary mutation that increases cancer risk. Considering that Mr. Shah had several siblings as well as a niece and two nephews who could potentially carry the same mutation and would therefore be at an increased risk of suffering from cancer, too, the same MST was offered to them. One of Mr. Shah’s sisters was already suffering from endometrial cancer (diagnosed at the age of 39), but the other family members were unaffected to date.
Choosing to know
In the end, Mr. Shah’s two unaffected sisters, his brother, his niece and both nephews opted to take the MST. The sister who was already suffering from cancer assumed she had the mutation and did not think the test was necessary. However, her status as a carrier was indirectly confirmed by the fact that, unfortunately, her son Amod, one of Mr. Shah’s nephews who took the MST, tested positive for the same mutation. Mr. Shah’s son Sahil also tested positive. Mr. Shah’s unaffected sisters, his brother and the niece and other nephew were relieved to have tested negative for this mutation and were therefore considered to be at an average population risk for cancer.
Prevention is better than cure
Both Amod and Sahil had therefore received advance warning of their increased risk of colorectal cancer and the other cancers that can be caused by this inherited mutation. Doctors have long established a recommended regimen of preventive screening tests for people suffering from Lynch syndrome, which include colonoscopies at a much earlier age (compared to after 50 for people at average risk) and at much more frequent intervals. Even adopting healthy life styles with plenty of physical exercise and diets high in fruits, vegetables, and fiber, avoiding alcohol and not smoking would benefit the two cousins, because carrying a high-risk mutation is not a death sentence. Not everyone with such a mutation goes on to develop cancer. But knowing you are at a higher risk can be a great motivation for looking out for your own and your family’s future health!
Disclaimer: The information provided in this article is in no way intended to replace expert medical advice. Always discuss the best possible course of action for your situation with your doctor.
Impacting Lives with Precision Medicine
In the News!
Study shows high prevalence of Hereditary Breast and/or Ovarian Cancer among patients in India
Breast cancer is the most common cancer in women all over the world and mutations in the BRCA1 and BRCA2 genes are most commonly associated with pre-disposition to Hereditary Breast and Ovarian Cancer (HBOC) syndrome. The study shows that the incidence of pathogenic gene mutations is high (~30%) in Indian patients referred for genetic testing to Strand, corroborating an earlier smaller study conducted by Strand, which showed similar findings. This is in contrast to studies on western patients, where the incidence is only about 10%. The study underscores the importance of testing at-risk individuals for inherited risk of BOC, particularly in the Indian context. Read more
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