New York, Dec 26: Cervical cancer is the second most common cancer in women and is responsible for nearly 10 percent of cancer deaths in women – particularly in developing countries. In India, it kills over 74,000 women every year.
Now, researchers have completed a systematic and comprehensive genomic analysis of cervical cancer in two different populations – identifying recurrent genetic mutations that were not previously found in cervical cancer.
The findings also capture the role that human papillomavirus (HPV), a common viral infection of the reproductive tract, plays in the development of cervical cancer.
“While we don’t have the complete answer yet in this case, what we are seeing is that, in two different populations, the causes of cervical cancer are similar and, fundamentally in both cases, it comes down to HPV-genome interaction,” said Matthew Meyerson, co-senior author of the paper and professor of pathology and medical oncology at Dana-Farber Cancer Institute in Boston.
The team examined the genetic code in the protein-coding regions of the genome – on samples from 115 cervical cancer patients from Norway and Mexico.
The study identified 13 mutations that occurred frequently enough across the samples to be considered significant in cervical cancer. Eight of these mutations had not been linked to the disease previously, and two had not previously been seen in any cancer type.
In each case, the researchers compared genomic data derived from cervical cancer tumours with genomic data from healthy tissue from the same individual to determine what may have gone wrong – or mutated – in the genome to allow the cancer to develop. The mutations identified in tumours but not in healthy tissues from the same individuals are referred to as somatic mutations.
“By analysing genomic data from diverse populations, we can discover patterns to disease progression in context of the full range of human genetic variation,” said co-senior author Helga Salvesen.
Among the most notable findings were somatic point mutations in the gene ERBB2, which was found in a small but significant subset of the tumours. Mutations in this gene, which is also known as Her-2, had not been previously been linked to cervical cancer, but it is a known oncogene common in breast cancer. Treatments exist that target the gene.
The most striking finding was to learn more about how HPV – a primary risk factor for cervical cancer – is driving the disease.
“Our findings further elucidate the key role HPV is playing in the development of cervical cancer, which in turn emphasises the importance of combating the disease by vaccinating against HPV,” Meyerson said.
The paper claimed the study bears important clinical implications for targeted therapeutics.
“It is hoped that, as we combine vaccination strategies and novel targeted therapies, we will be better able to combat cervical cancer,” the paper added.