A groundbreaking study conducted by a research team led by Johns Hopkins Medicine has revealed that a healthy diet may reduce the risk of low-risk prostate cancer progressing to a more aggressive state in men undergoing active surveillance. Active surveillance is a clinical option in which men with lower-risk cancer are carefully monitored for progression instead of undergoing treatments that could have undesirable side effects or complications. The study, published in JAMA Oncology, provides scientific evidence that changes in diet and nutrition can potentially improve the prognosis for men diagnosed with low-grade prostate cancer.
Prostate cancer is assigned to a grade group based on the appearance of the sampled cells compared to normal prostate tissue. Grade groups range from 1 to 5, with grade group 1 indicating indolent cancer cells that do not spread and grade group 5 indicating aggressive cancer cells that can metastasize if left untreated. During active surveillance, biopsies are regularly performed to monitor for changes that would move the cancer to a higher grade group, a process known as grade reclassification. The researchers aimed to evaluate the effectiveness of diet and lifestyle modifications in reducing the risk of cancer progression in men on active surveillance.
The study analyzed the dietary patterns of 886 men diagnosed with grade group 1 prostate cancer who were enrolled in the active surveillance program at Johns Hopkins Medicine. Using the Healthy Eating Index (HEI) and the Dietary Inflammatory Index (DII), the researchers assessed the association between diet quality and the risk of grade reclassification. The results showed a statistically significant inverse relationship between adherence to a high-quality diet, as indicated by high HEI scores, and the risk of grade reclassification during active surveillance. Each 12.5-point increase in the HEI score was associated with a 15% reduction in reclassification to grade group 2 or greater, and a 30% reduction in reclassification to grade group 3 or greater.
Lower inflammation potential was identified as one of the mechanisms through which a high-quality diet reduced the risk of prostate cancer progression. However, no association was found between grade reclassification and baseline DII/E-DII scores, suggesting that inflammation may play a role in driving the progression from a healthy prostate to cancer. The study has certain limitations, including self-reported dietary data, potential response bias, and the study population predominantly consisting of white men with grade group 1 disease, which may limit the generalizability of the findings. Future studies with more diverse populations are needed to validate the association between diet quality and reduced risk of prostate cancer progression.
Overall, the findings of this study suggest that dietary modifications, particularly adherence to a high-quality diet, may play a significant role in reducing the risk of low-risk prostate cancer progressing to a more aggressive state. The researchers emphasize the importance of counseling men on active surveillance about making behavioral changes, including improvements in diet quality, to potentially improve their prognosis. Further research with diverse populations is needed to confirm the association between diet quality and prostate cancer progression risk.