New classification system for prostate cancer improves diagnostics

February 2021 Medical Research Willem van Altena

Prostate cancer is one of the most prevalent types of cancer in men worldwide. Because of its heterogenous character, prostate cancer can present many different forms, each with their own outcome and therapeutic needs. Some types of prostate cancer are relatively less life-threatening, with slow growth rate and low risk of metastasis. Other types present a more acute danger and can quickly spread to other organs and tissues. Diagnosing exactly what type of prostate cancer a patient has is not easy since there are no specific biomarkers that adequately point to a clear determination. Therefore, prostate cancer treatment is mostly based on prognostic variables from a staging system with four stages, and on factors such as the Gleason grade and the PSA-level.

Recently, however, the American Joint Committee on Cancer (AJCC) has devised a new way of classifying prostate cancer, allowing for a more precise diagnosis and prognosis. A team from the university of Michigan, led by professor dr. Robert T. Dess describes an international cohort study into a new prognostic classification system for patients with non-metastasized prostate cancer. The study was published in JAMA Oncology.

The new system, which is named STAR-CAP, was constructed using data from almost 20.000 prostate cancer patients. According to professor Dess, who holds a chair in radiation oncology, the new system can improve the prognostics surrounding prostate cancer, enabling doctors to provide more insight for their patients regarding treatment options.

The STAR-CAP system awards points between 1 and 8 for a number of variables, such as age, Gleason grade, tumour size, PSA-values and the degree of cell abnormality in the prostate. Depending on the total score, patients are then divided into three categories, that are in turn split into three subcategories. As a result, there are nine categories.

The study involved data from 19,684 prostate cancer patients over a period of 10 years. Median follow-up was 71.8 months, but 20,7% of patients were followed for more than 10 years. In total, 12,421 patients were treated by surgery and 7,263 by radiotherapy. The 10-year mortality was higher in the STAR-CAP system than the traditional system, but 22% of all patients were downgraded from the highest stage (3A) to the lowest (1A). Dess believes that the new, more accurate staging system will provide more solid information to base treatments and prognosis on. The STAR-CAP method can be applied worldwide by medical professionals and researchers.

Source

Development and Validation of a Clinical Prognostic Stage Group System for Nonmetastatic Prostate Cancer Using Disease-Specific Mortality Results From the International Staging Collaboration for Cancer of the Prostate JAMA Oncol. 2020;6(12):1912-1920. doi:10.1001/jamaoncol.2020.4922