hormone therapy
Prostate Cancer: Combined Biopsy Strategy Makes for More Accurate Diagnosis
Posted on by Dr. Francis Collins
Last year, nearly 175,000 American men were diagnosed with prostate cancer [1]. Most got the bad news after a blood test or physical exam raised concerns that warranted a biopsy of the prostate, a walnut-sized gland just below the bladder.
Traditional biopsies sample tissue from 12 systematically placed points within the prostate that are blind to tumor locations. Such procedures have helped to save many lives, but are prone to missing or misclassifying prostate cancers, which has led doctors both to over and under treat their patients.
Now, there may be a better approach. In a study of more than 2,000 men, NIH researchers and their colleagues recently found that combining the 12-point biopsy with magnetic resonance imaging (MRI)-targeted biopsy during the same session more accurately diagnoses prostate cancer than either technique alone [2].
The findings address a long-standing challenge in prostate cancer diagnostics: performing a thorough prostate biopsy to allow a pathologist to characterize as accurately as possible the behavior of a tumor. Some prostate tumors are small, slow growing, and can be monitored closely without treatment. Other tumors are aggressive and can grow rapidly, requiring immediate intervention with hormonal therapy, radiation, or surgery.
But performing a thorough prostate biopsy can run into technical difficulties. The 12-point biopsy blindly samples tissue from across the prostate gland, but it can miss a cancer by not probing in the right places.
Several years ago, researchers at the NIH Clinical Center, Bethesda, MD, envisioned a solution. They’d use specially designed MRI images of a man’s prostate to guide the biopsy needle to areas in the prostate that look suspicious and deserve a closer look under a microscope.
Through a cooperative research-and-development agreement, NIH and the now- Florida-based Philips Healthcare created an office-based, outpatient prostate biopsy device, called UroNav, that was later approved by the Food and Drug Administration. The UroNav system relies on software that overlays MRI images highlighting suspicious areas onto real-time ultrasound images of the prostate that are traditionally used to guide biopsy procedures.
The new technology led to a large clinical study led by Peter Pinto, a researcher with NIH’s National Cancer Institute. The study results, published in 2015, found that the MRI-targeted approach was indeed superior to the 12-point biopsy at detecting aggressive prostate cancers [3].
But some doctors had questions about how best to implement the UroNav system and whether it could replace the 12-point biopsy. The uncertainty led to a second clinical study to nail down more answers, and the results were just published in The New England Journal of Medicine.
The research team enrolled 2,103 men who had visible prostate abnormalities on an MRI. Once in the study, each man underwent both the 12-point blind biopsy and the MRI-targeted approach—all in a single office visit. Based on this two-step approach, 1,312 people were diagnosed with prostate cancer. Of that total, 404 men had evidence of aggressive cancer, and had their prostates surgically removed.
The researchers then compared the diagnoses from each approach alone versus the two combined. The data showed that the combined biopsy found 208 cancers that the standard 12-point biopsy alone would have missed. Adding the MRI-targeted biopsy also helped doctors find and sample the more aggressive cancers. This allowed them to upgrade the diagnosis of 458 cancers to aggressive and in need of more full treatment.
Combining the two approaches also led to more accurate diagnoses. By carefully analyzing the 404 removed prostates and comparing them to the biopsy results, the researchers found the 12-point biopsy missed the most aggressive cancers about 40 percent of the time. But the MRI-targeted approach alone missed it about 30 percent of the time. Combined, they did much better, underestimating the severity of less than 15 percent of the cancers.
Even better, the combined biopsy missed only 3.5 percent of the most aggressive tumors. That’s compared to misses of about 17 percent for the most-aggressive cancers for the 12-point biopsy alone and about 9 percent for MRI-targeted biopsy alone.
It may take time for doctors to change how they detect prostate cancer in their practices. But the findings show that combining both approaches will significantly improve the accuracy of diagnosing prostate cancer. This will, in turn, help to reduce risk of suboptimal treatment (too much or too little) by allowing doctors and patients to feel more confident in the biopsy results. That should come as good news now and in the future for the families and friends of men who will need an accurate prostate biopsy to make informed treatment decisions.
References:
[1] Cancer State Facts: Prostate Cancer. National Cancer Institute Surveillance, Epidemiology, and End Results Program.
[2] MRI-targeted, systematic, and combined biopsy for prostate cancer diagnosis. Ahdoot M, Wilbur AR, Reese SE, Lebastchi AH, Mehralivand S, Gomella PT, Bloom J, Gurram S, Siddiqui M, Pinsky P, Parnes H, Linehan WM, Merino M, Choyke PL, Shih JH, Turkbey B, Wood BJ, Pinto PA. N Engl J Med. 2020 Mar 5;382(10):917-928.
[3] Comparison of MR/ultrasound fusion-guided biopsy with ultrasound-guided biopsy for the diagnosis of prostate cancer. Siddiqui M, Rais-Bahrami, George AK, Rothwax J, Shakir N, Okoro C, Raskolnikov D, Parnes HL, Linehan WM, Merino MJ, Simon RM, Choyke PL, Wood BJ, and Pinto PA. JAMA. 2015 January 27;313(4):390-397.
Links:
Prostate Cancer (National Cancer Institute/NIH)
Video: MRI-Targeted Prostate Biopsy (YouTube)
Pinto Lab (National Cancer Institute/NIH)
NIH Support: National Cancer Institute; NIH Clinical Center
Personalized Combination Therapies Yield Better Cancer Outcomes
Posted on by Dr. Francis Collins
Gratifying progress has been made recently in an emerging area of cancer medicine called precision oncology. It’s a bold attempt to target treatment to the very genes and molecules driving a cancer, aiming to slow or even halt its growth. But there’s always more to learn. Now comes evidence that, while a single well-matched drug might be good, a tailored combination of drugs that attack a cancer in multiple ways at once might be even better.
The findings come from the I-PREDICT clinical trial, which treated people with advanced cancer who hadn’t benefited from previous therapy [1]. The NIH-funded team found that analyzing a tumor’s unique genetic and molecular profile provided enough information to recommend individualized combination therapies to patients. What’s more, patients who followed their individualized combination therapies most closely lived longer, with longer periods of progression-free disease, than did those who took fewer of the recommended drugs.
In most previous clinical trials of precision oncology, researchers have relied on a tumor’s unique profile to identify a single, well-matched drug to treat each patient. But cancer is complex, and, just as with certain infectious diseases, tumors commonly develop resistance to a single drug.
In the trial reported in Nature Medicine, researchers led by Razelle Kurzrock and Jason Sicklick, University of California, San Diego, wondered if they could improve treatment responses by tailoring combinations of cancer drugs to target as many molecular and genetic changes in a person’s cancer as possible.
To test the potential for this strategy to work, the researchers enrolled 83 people with various cancers that had advanced despite previous treatment. Tumor tissue from each patient was run through a comprehensive battery of tests, and researchers sequenced hundreds of genes to look for telltale alterations in their DNA.
They also looked for evidence that a cancer had defects affecting the DNA “mismatch repair” pathway, which causes some tumors to generate larger numbers of mutations than others. Mismatch repair defects have been shown to predict better responses to immunotherapies, which are designed to harness the immune system against cancer .
With all the data in hand, a special panel of oncologists, pharmacologists, cancer biologists, geneticists, surgeons, radiologists, pathologists, and bioinformatics experts consulted to arrive at the right customized combination of drugs for each patient.
The panel’s findings were presented to the health care team working with each patient. The physician for each patient then had the final decision on whether to recommend the treatment regimen, balancing the panel’s suggestions with other real-world factors, such as a patient’s insurance coverage, availability of drugs, and his or her treatment preference.
Ten patients decided to stick with unmatched treatment. But 73 participants received a customized combination therapy. As no two molecular profiles were identical, the customized treatment regimens varied from person to person.
Many people received designer drugs targeting particular genetic alterations. Some also received checkpoint inhibitor immunotherapies to unleash the immune system against cancer. Four people also were treated with hormone therapies in combination with molecularly targeted drugs. In all, most regimens combined two to five drugs to target each cancer profile.
Participants were followed until their cancer progressed, they could no longer take treatment, or they died. For each person, the researchers calculated a “matching score,” roughly defined as the number of molecular alterations matched to administered drug(s), with some further calculations.
The evidence showed that those with matching scores greater than 50 percent, meaning more than half of a tumor’s identified aberrations had been targeted, were more likely to have stopped the progression of their cancers. Importantly, half of patients with the higher matching scores had prolonged stable disease (six months or longer) or a complete or partial remission. Similar results were attained in only 22 percent of those with low or no matching scores.
These encouraging results suggest that customized combinations of targeted treatments will help to advance precision oncology. However, there are still many challenges. For example, many of the combinations used in the study have not yet been safety tested. The researchers managed the potential risk of toxicities by starting patients on an initial low dose and having their physicians follow them closely while the dose was increased to a level well-tolerated by each individual patient.
And indeed, they saw no evidence that those receiving a greater proportion of “matched” drugs (i.e. those with a higher matching score) were more likely to experience adverse effects than those who took fewer drugs. So, that’s an encouraging sign.
The researchers are now enrolling patients in a new version of the I-PREDICT trial. Unlike the initial plan, patients are now being enrolled prior to receiving any treatment for a recently diagnosed aggressive, often-lethal form of cancer. The hope is that treating patients with well-matched, multi-drug treatment combinations early will yield even better results than waiting until standard treatment has failed. If correct, it would mark significant progress in building the future of precision oncology.
Reference:
[1] Molecular profiling of cancer patients enables personalized combination therapy: the I-PREDICT study. Sicklick JK, Kato S, Okamura R, Schwaederle M, Hahn ME, Williams CB, De P, Krie A, Piccioni DE, Miller VA, Ross JS, Benson A, Webster J, Stephens PJ, Lee JJ, Fanta PT, Lippman SM, Leyland-Jones B, Kurzrock R. Nat Med. 2019 Apr 22.
Links:
Precision Medicine in Cancer Treatment (National Cancer Institute/NIH)
Study of Molecular Profile-Related Evidence to Determine Individualized Therapy for Advanced or Poor Prognosis Cancers (I-PREDICT) (Clinicaltrials.gov)
Razelle Kurzrock (University of California, San Diego)
Jason Sicklick (University of California, San Diego)
NIH Support: National Cancer Institute
Most Women with Early-Stage Breast Cancer Don’t Need Chemo
Posted on by Dr. Francis Collins
Credit: National Cancer Institute, NIH
In the last few days, you may have heard that there’s been a significant development in the management of breast cancer. So here’s the NIH Director’s blog description of what’s happened. Each year, as many as 135,000 American women who’ve undergone surgery for the most common form of early-stage breast cancer face a difficult decision: whether or not to undergo chemotherapy. Genetic testing of tumor tissue has helped to inform some of these decisions, with women whose tumors score high on the breast cancer recurrence scale likely to benefit from chemo, and those with low-scoring tumors able to skip the cost and potentially serious side effects. But there’s been a catch: most tumors score somewhere in the middle, leaving women and their doctors uncertain about what to do.
Now, thanks to the long-awaited results of a large, NIH-funded clinical trial, we finally have an answer. About 70 percent of women with hormone receptor (HR)-positive, HER2-negative, axillary lymph node-negative breast cancer—including those with mid-range scores on the cancer recurrence scale—do not benefit from chemotherapy [1]. These findings promise to spare a great many women with breast cancer from unnecessary exposure to costly and potentially toxic chemotherapy.
