A multidisciplinary team of doctors from the University of California at Los Angeles (UCLA) has discovered that a new method can be used, which combines biopsy guided by magnetic resonance imaging or MRI along with the traditional method, to increase the detection rate of prostate cancer. This has allowed to detect up to 33 percent more cancers compared to traditional, guided by ultrasound images, which can not clearly show the location of tumors in the prostate gland.
Ultrasound has been used to visualize the prostate in order to take a representative sample of tissue to perform a biopsy. The introduction of MRI has allowed doctors to see specific lesions in the prostate and only take tissue samples from those points. But the two sampling methods are often not used in combination.
In this three-year study, published in 'JAMA Surgery', a strategy that combines both methods of sampling led to the detection of up to 33 percent more cancers than standard methods. According to the lead author, Dr. Leonard Marks, the findings could help generate a major change in the way prostate biopsies are performed.
“Our research suggests that different biopsy methods identify different tumors,” explains Marks, who holds the Jean B. deKernion chair in the department of urology at the David Geffen School of Medicine at UCLA. To maximize our ability to identify prostate cancer, we must take advantage of all the information we can. Our cancer detection rate, while using different methods together, exceeds that of using either of the two methods separately. In this case, one plus one equals three. “
The study is the first to directly compare the different biopsy sampling methods in the same group of men. Previous research demonstrated the advantages of an MRI-guided biopsy, but it was not clear how to use the new technology. This trial establishes that both systematic and specific lesion sampling are necessary to maximize the accuracy of the prostate biopsy.
In the last decade, MRI-guided biopsy methods, which are more specific because they can accurately show the locations of the lesions in the prostate, have been used more frequently. However, some tumors are not visible, so these cancers may not be detected.
In the study of 300 people, 248 men had a visible prostate lesion on MRI. By using all the information and biopsy methods available together, the researchers detected cancer in 70 percent of them. Another 52 men had no visible lesions on MRI, but it was found that 15 percent had cancer through the traditional ultrasound method, confirming that MRI does not identify all tumors.
“Men who are being evaluated for prostate cancer must first receive an MRI before the biopsy,” says Marks, who is a member of UCLA's Jonsson Comprehensive Cancer Center. When there is an MRI injury, doctors should take systematic and targeted biopsies together to have the best chance of finding cancer. Even if the MRI is negative for the lesions, men at risk, including those with high levels of prostate-specific antigen, prostate nodule, or family history, should still receive a traditional systematic biopsy. “
The identification of the precise location of the cancerous tissue in the prostate is especially important since the treatments are becoming more specific. While surgical removal of the entire gland, known as prostatectomy, is a common method of treatment, emerging treatments, such as focal therapy, aim to eliminate only cancerous tissue in the gland and preserve healthy tissue.
“Improving our ability to see the location of cancer in the prostate in real time opens the door to treatment innovations,” Marks reasoned. If we can identify the location of the tumors and place biopsy needles directly on them, why not find a way to destroy the tumor in place? “