Friday March 22, 2019

Celebrate February 4 As World Cancer Day

In India, the application of cancer genetic testing in therapeutic decisions has seen tremendous increase particularly in lung, breast, gastrointestinal and colorectal cancers

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Cancer
Cancer Ribbon. Pixabay

The gene is a unit of inheritance of our DNA that determines our characteristics including physical, behavioural and clinical and the term ‘hereditary’ means passed from the genes of a parent to the child. In cancer genetics, often these terms are used interchangeably.

The majority of us have a perception of genetics in the terms of hereditary lineage. However, there are quite of few gene mutations which are not inherited but acquired during the course of individual’s life due to a set of predisposing events or lifestyle habits.

This brings us to the question: “What can genetics do in cancer apart from telling the hereditary predisposition and vulnerability to cancer?” The answer is the D-P-T (Diagnosis-Prognosis-Therapeutics) Triangle.

For example: A 63-year-old man develops lung cancer without having any first/second degree relatives diagnosed with cancer. These are sporadic cancers constituting more than 85 per cent of all newly-diagnosed cancers. Scientific research has contributed significantly to our understanding of lung cancer, its onset and the importance of screening cancer-causing genes for mutations which helps physicians to provide targeted therapy to kill or overcome cancer.

Cancer genetics: Beyond hereditary cancer (Health Notes) (February 4 is World Cancer Day).

The presence of EGFR gene mutation in lung cancer implies that one particular class of anti-cancer drugs are highly effective in killing lung cancer cells and thus improving the quality of life and survival of a patient. Beyond this, research identified a subsequent secondary mutation in the EGFR gene in patients who are already on targeted drug. These mutations make the cancer cells resistant to the drug.

To address this challenge, fourth generation drugs are in the pipeline that could specifically kill those cancer cells that have developed resistance to the first, second and third generation drugs. This is a classic example of how genetic testing has helped in treatment planning and management of the cancer and is an example of cancer genetics beyond heredity.

* Cancer genetics in diagnosis

An accurate diagnosis of a type or subtype of cancer can be helpful to better manage the disease. There are multiple other cases where mutation in genes confirm the diagnosis and hence guide the further course of action. For example, in leukemia, there are a set of genes, if mutated, that help in distinguishing myeloproliferative neoplasm (MPN – a type of leukemia) from other benign causes of cytopenias (reduction of mature blood cells).

* Cancer genetics in prognosis

Prognosis in simple terms mean prediction of how the disease is going to progress. This application is helpful to understand whether the disease requires aggressive treatment or not. For example: There is a standard recommendation of IGHV gene mutation testing in chronic lymphocytic leukemia.If this gene is mutated, clinical studies have shown that these patients do not show an aggressive disease phenotype and hence may not require aggressive treatment. However, for patients who are not mutated for the IGHV gene, clinical studies have shown that the disease progresses aggressively and the treatment regimen could be re-worked for improving the quality of life and survival of these patients.

Cancer survivor, flickr

* Cancer genetics in therapeutics

The term targeted therapy would not be the same in cancer, if not for genetics.There are some genes which help in treatment decision called oncogenes/tumor suppressors, wherein a sporadic mutation changes the function of the gene-inducing cellular processes leading to uncontrolled cell division causing cancer. This intrinsic property of the cancer cell is advantageous to drug manufacturers for developing molecules that block the protein and inhibit cancer progression or kill the cancer cells.

Also Read- Here’s How The Microbes Help You Make a Perfect Cup of Coffee

In India, the application of cancer genetic testing in therapeutic decisions has seen tremendous increase particularly in lung, breast, gastrointestinal and colorectal cancers. (IANS)

Next Story

To Ensure Transparency, WHO Panel Aims for Registry of All Human Gene-Editing Research

The WHO panel's statement said any human gene-editing work should be done for research only, should not be done in human clinical trials, and should be conducted transparently.

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A researcher works with embryos at a lab in Shenzhen in southern China's Guandong province, Oct. 9, 2018. An expert committee Tuesday called for the U.N. health agency to create a global registry of scientists working on gene editing. VOA

It would be irresponsible for any scientist to conduct human gene-editing studies in people, and a central registry of research plans should be set up to ensure transparency, World Health Organization experts said Tuesday.

After its first two-day meeting in Geneva, the WHO panel of gene-editing experts — which was established in December after a Chinese scientist said he had edited the genes of twin babies — said it had agreed on a framework for setting future standards.

It said a central registry of all human genome-editing research was needed “in order to create an open and transparent database of ongoing work,” and asked the WHO to start setting up such a registry immediately.

“The committee will develop essential tools and guidance for all those working on this new technology to ensure maximum benefit and minimal risk to human health,” Soumya Swamanathan, the WHO’s chief scientist, said in a statement.

FILE - He Jiankui, left, and Zhou Xiaoqin work a computer at a laboratory in Shenzhen in southern China's Guangdong province, Oct. 10, 2018. Chinese scientist He says he helped make the world's first genetically edited babies.
– He Jiankui, left, and Zhou Xiaoqin work a computer at a laboratory in Shenzhen in southern China’s Guangdong province, Oct. 10, 2018. Chinese scientist He says he helped make the world’s first genetically edited babies. VOA

A Chinese scientist last year claimed to have edited the genes of twin baby girls.

News of the births prompted global condemnation, in part because it raised the ethical specter of so-called “designer babies” — in which embryos can be genetically modified to produce children with desirable traits.

Top scientists and ethicists from seven countries called last week for a global moratorium on gene editing of human eggs, sperm or embryos that would result in such genetically-altered babies — saying this “could have permanent and possibly harmful effects on the species.”

The WHO panel’s statement said any human gene-editing work should be done for research only, should not be done in human clinical trials, and should be conducted transparently.

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After its first two-day meeting in Geneva, the WHO panel of gene-editing experts — which was established in December after a Chinese scientist said he had edited the genes of twin babies — said it had agreed on a framework for setting future standards. Pixabay

“It is irresponsible at this time for anyone to proceed with clinical applications of human germline genome editing.”

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The WHO’s director-general, Tedros Adhanom Ghebreyesus, welcomed the panel’s initial plans. “Gene editing holds incredible promise for health, but it also poses some risks, both ethically and medically,” he said in a statement.

The committee said it aims over the next two years to produce “a comprehensive governance framework” for national, local and international authorities to ensure human genome-editing science progresses within agreed ethical boundaries. (VOA)