ASCO 2011: Prostate Cancer in Older Adults: To Treat or Not to Treat?

At the session on Management of Prostate Cancer in Older Adults: To Treat or not to Treat, Anthony D’Amico, William Dale, and Shabbir Alibhai all lent their clinical expertise in treating prostate cancer to outline the latest recommendations for screening and treating men for prostate cancer.

Dr. Dale was the first to take the podium. After describing some of the research that helped shape the new treatment guidelines, he said that, to him, the decision of whether to treat or not to treat is a question of balancing the harms and benefits. He noted that the leading causes of death for older men with prostate cancer, by grade, are cardiovascular disease, other cancers besides cancer of the prostate, and-only third-is prostate cancer itself.

He next discussed the pitfalls inherent to life expectancy estimations, saying that using co-morbidity, “get up and go” tests, among others, are ways that MDs generally determine life expectancy. But that that must be only one part of the equation, and that physicians have to also “figure out the benefits and figure out the harms, and talk to patients about preferences and values.” He ended by saying that for every 48 cases that are tested, 1 prostate cancer death is prevented.” He outlined his own way of determining whether or not to treat, saying that the default decision is not to screen, but to determine baseline risk based on race and family history. Next determine if life expectancy is greater or less than 10 years, based on self-reported health; geriatric assessment; and comorbidities. Finally, he discusses follow-up for a significant positive test with patients up front, and if necessary, a biopsy. After biopsy he connects with patients to assess their values and preferences.

Anthony D’Amico, Localized Disease

Dr. D’Amico, one of the authors on the ACS “Guidelines for the Early Detection of Prostate Cancer,” questioned the accuracy of MDs predictions of survival, considering the current prognostic tools they have to estimate life expectancy in terminally ill cancer patients. He believes the “fair” evidence to support life expectancy predictions include performance status, clinical/biochemical parameters, and the MDs assessment, and stated that the MDs estimate of life expectancy alone is not sufficient evidence.

“When we design randomized trials across the board, we need level -1 evidence that treatment or screening is effective.” He went on to say “Why not use comorbidity instead of age to determine whether a patient should receive treatment and how?” He went on to point out that with combined modality therapy, the patients with no comorbities benefited much more than those with comorbidities.

Shabbir M. H. Alibhal: Biochemical Recurrence

Dr. Alibhal began his talk with an outline of what he’d cover, including a discussion of recurrent prostate cancer, a look at when it should be treated, including prognosis of recurrent prostate cancer, and efficacy and toxicity of treatment, and then a discussion of whether or not age matters.

Alibhal first noted that, in the past, types of recurrence were either local or systemic, but now recurrence is measured biochemically two; biochemical too. In fact, widespread PSA testing post radical treatment have made it so that biochemical recurrent is a “relatively new stage of disease.” He noted that PSA monitoring picks up disease activity 1-2 years earlier.

Other important characteristics of biochemical recurrence are that it is the most common form of recurrence; it often occurs years after initial treatment of prostate cancer, in middle-aged men who have aged in the interim; local recurrence is hard to distinguished from systemic recurrence, and local recurrence is also treated very differently from biochemical recurrence.

He cited data saying that estimates of biochemical recurrence range from 15-33% at 5 years, but for those patients who receive electron beam radiation therapy, the biochemical recurrence rate at 5 years is 16-57%. Alibahl stated that clinical stage, Gleason score, and PSA level are all linked to risk of biochemical recurrence.

Alibahl then moved on to a discussion of “Should we treat them or not?” saying that prognosis varies widely, and that PSA doubling time, Gleason score, and time to biochemical recurrence should all be used to determine treatment course. He noted that there will be an abstract called "Feasibility of triweekly docetaxel-based chemotherapy for elderly patients (age 75 and older) with castration-resistant prostate cancer" that should provide some important data, here at the meeting.

Alibahl finishes by saying that he believes the data suggest that that ADT could be considered in men with biochemical recurrence after radical prostatectomy  if men have a high Gleason score or a rapidly rising PSA-and that some would argue that treatment should wait until the PSA reaches 10. He cites toxicity/side effects as being a major factor in determining whether to treat, citing the side effects as being sexual dysfunction, diabetes, osteoporosis, metabolic syndromes, cardiac issues (though these are debated), muscle atrophy, fatigue, and possibly cognitive dysfunction.

During the Q & A portion of the session, D’Amico described the case of an imaginary man who represents a borderline risk “someone who is older, maybe 72, PSA level 3.6, African American, his exam is benign, no family history, but has diabetes for 15 years and is starting to have renal insufficiencies.” He asked, “Where do you put this person, who kind of falls in the middle?

Dale answered, “These are the hard cases. We’re talking about the really healthy people and the really sick people-we know what to do with them. We need to have a careful conversation with the patients, about the disease and the consequences of treating the disease, and get a sense of where they are as far as life expectancy. At the end of the day I let patients tell me how they feel. D’Amico summarized by saying “When in doubt, ask the patient.”