Researchers at the Duke Cancer Institute along with other cancer centers, in the largest analysis of its kind have found that the organ site where prostate cancer spreads has a direct impact on a man’s survival.
They found that men with lymph-only metastasis statistically have the longest overall survival possibility, while those with liver involvement the worst. Men with lung and bone metastasis fall in the middle of these two groups.
It has been generally assumed, based on smaller studies, ”that the site of metastasis in prostate cancer affects survival, but prevalence rates in organ sites were small, so it was difficult to provide good guidance,” said Susan Halabi, Ph.D., Professor of Biostatistics at Duke and lead author of the study published online March 7 in the Journal of Clinical Oncology.
Because of the very large numbers of men in the study the researchers were “able to compare all of the different body (organ) sites and provide information that could be helpful in conveying prognosis to patients,” Halabi said. “This information could also be used to help guide treatment approaches using either hormonal therapy or chemotherapy.”
The study combined data from nine large, phase III clinical trials totaling 8,736 men who had undergone standard treatment with the chemotherapy.
The researchers characterized the site of metastases into four groups: lung, liver (without lung), lymph node only, bone with or without lymph nodes and no other organ metastases.
Nearly 73 percent of the men had bone metastases, and their overall median survival was just over 21 months. Men with lymph involvement only were the smallest subset—6.4 percent—but had the longest median survival at about 32 months.
Men with liver metastasis represented 8.6 percent of the study population and had the worst median survival of nearly 14 months. Men with lung metastases had a median survival of 19 months, and represented 9.1 percent of the study population.
“These results should help guide clinical decision-making for men with advanced prostate cancer,” Halabi said. “They also suggest that prognostic subgroups should be considered for investigational therapies that are tested in clinical trials.”
It isn’t clear why some prostate cancers spread to which organs. Understanding what makes or allows which cancer go to which organ might be very helpful in our search to end prostate cancer.