“Genome Sequencing”, a post by student Lydia

Although there are many diverse types of cancer, until recently, these varied diseases were treated very similarly. Different types of cancer can be classified by differences in the mutations of the tumor’s genes. Medicines are then developed based off of these mutations. For well-known mutations in more common types of cancer, medicines are more easily developed to specifically target those diseases; these specialized medicines weren’t developed for all types of cancer. These medicines, however, were applied to a large variety of cancers, even though they were largely ineffective in treating those cancers that had differing mutations.

Recent genome-sequencing technology and strategies have not only fostered a better understanding of cancer, but helped pinpoint the exact mutations that a medicine must target. This specialization has, according to Wired magazine, “dramatically improved the outlook for people with…notoriously hard-to-treat cancers.” Genome sequencing has opened up a new world for cancer diagnosis and treatment alike.

Genome sequencing involves identifying and characterizing RNA or DNA sequences, meaning it identifies the bases—but more importantly, it can identify mutations. The first attempts at cancer genome sequencing were made in 1997 by the Cancer Genome Anatomy Project, which continued its involvement with the project for years. Later, in 2007, as the technology gained recognition, the International Cancer Genome Consortium was founded. Initiatives like these worked to not only develop the technology, but to make it accessible to patients. As of April 2014, according to the publication Seminars in Cancer Biology, 10,000 tumor genomes had been sequenced, and the price of sequencing a “whole human genome” was $1,000. This price was quite a leap from the 2007 cost of $350,000.

As genome sequencing becomes more affordable and therefore more accessible, more uncommon mutations will be treatable. In some cases, these mutations had never before been fully linked to the disease. One patient in 2014 with multiple myeloma had a cancer-causing mutation in her BRAF gene, which had only been linked to a mere 5% of multiple myeloma patients. Because the genome sequencing successfully detected the BRAF gene mutation, the patient had the option to receive much more specialized care and medicine that would target her specific genetic mutation.

Genome sequencing is not only an important development in the realm of scientific research because it allows for cancer tumors to be better understood, but it illustrates the overwhelming diversity of cancer. The patient with multiple myeloma is an example of this diversity; the variation in cancer-causing mutations is staggering. Genome sequencing also allows for a greater understanding of the “hallmarks” of cancer, which scientists consider the definition of the disease’s ability to successfully infect a patient, as well as what technically differentiates a cancer cell from a normal cell.

The recent developments of genome sequencing have had an impact on these hallmarks of cancer, which are constantly evolving as new discoveries are made. A condition that is extensive in cancer is a state called aneuploidy, which is identified as a lack of correspondence between the number of chromosomes in the cells’ nuclei and the correct number of chromosomes that species should possess. Genome duplication in cancer cells has been linked to causing aneuploidy, and therefore genome duplication is emerging as a potential hallmark of cancer. If genome-duplication-caused aneuploidy were definitively established as a hallmark for cancer (and the research exists to prove that it should be), then genome sequencing could be used to map these duplications and to possibly evade the extensive aneuploidy that occurs in cancer cells.

Although genome sequencing is a fantastic innovation, it does raise some troubling questions. Because of its exorbitant price, genome sequencing is only accessible by some cancer patients; if every patient were to have access to a sequence of their entire human genome, it could potentially influence the process of that patient’s treatment—and even their possible recovery. Therefore, the goal should be to lower the price of the sequencing, which the scientific community is already working towards. The benefits to genome sequencing are very real: personalized, specialized cancer treatment is within the reach of modern science—and within the reach of patient’s budgets.

References:

Giusti, Kathy. “Cancer Research: Not a One-Size-Fits-All Approach | WIRED.”Wired.com. Conde Nast Digital, 14 Aug. 2014. Web. 12 Feb. 2015.

Wang, Edwin, Naif Zaman, and Shuana McGee. “Predictive Genomics: A Cancer Hallmark Network Framework for Predicting Tumor Clinical Phenotypes Using Genome Sequencing Data.” Seminars in Cancer Biology 30 (2015): 4-12. Predictive Genomics: A Cancer Hallmark Network Framework for Predicting Tumor Clinical Phenotypes Using Genome Sequencing Data. Seminars in Cancer Biology, 08 Apr. 2014. Web. 12 Feb. 2015.