Testing for Tumor Mutations: Liquid Biopsy Versus Traditional Biopsy


Liquid biopsies, virtually unknown even a year or two ago, are becoming common tools in precision diagnostics for cancer. Here, I will try to explain some of the more important differences between liquid and “traditional” tumor biopsies.

Biopsies of solid tumors (e.g., lung, breast, or brain tumors) involve surgically removing a small part of a tumor and sending it to pathology lab. In the last few years, doctors have also started to send some tumor samples to special service labs that analyze tumor DNA for the presence of cancer-related mutations.

By definition, regular biopsies can be intrusive and are sometimes associated with side effects, such as bleeding or infection. However, they provide some really essential information; i.e., the histology and grade of the tumor and other tumor characteristics necessary to determine the best choice of treatment. For lung cancer, for example, a biopsy determines the type of tumor—adenocarcinoma, squamous cancer, small-cell lung cancer, or another, less common type. For breast cancer, a routine test will determine if the tumor expresses estrogen, progesterone receptors, and a protein called HER2. These tests are critically important in guiding treatment choices. If mutational analysis of cancer-related genes is also performed (which doesn’t always happen, unfortunately), it may guide treatment with targeted drugs. Continue reading…


Low Risk Prostate Cancer Not Always Low Risk

“More and more men who believe they have low-risk prostate cancers are opting for active surveillance, forgoing treatment and monitoring the cancer closely with prostate-specific antigen (PSA) tests, digital rectal exams and ultrasounds at regular intervals to see if their tumors are growing. Nearly 400 men are now enrolled in the UCLA Active Surveillance program, the largest in Southern California.

“However, according to a new UCLA study, selection of men for active surveillance should be based not on the widely used conventional biopsy, but with a new, image-guided targeted prostate biopsy. The new biopsy method, pioneered by a multi-disciplinary team on the Westwood campus, is now a routine part of the UCLA active surveillance program.”