Prostate Cancer Treatment Update

WebMD Live Events Transcript

William K. Oh, MD, from the Dana-Farber Cancer Institute, joined us on March 23 to discuss the latest treatments for prostate cancer.

The opinions expressed herein are the guests' alone and have not been reviewed by a WebMD physician. If you have questions about your health, you should consult your personal physician. This event is meant for informational purposes only.

MODERATOR:
Welcome to WebMD Live, Dr. Oh. Thank you for joining us today. We have a number of questions from our members. Let's get started on them.

MEMBER QUESTION:
I am confused about my doctor's recommendation regarding the use of Proscar and/or Avodart for benign prostatic hyperplasia (BPH). I am using Proscar but have experienced a declined sex interest plus a decline in ejaculation. Does one treatment have an advantage over the other?

OH:
Both Proscar and Avodart are hormonal therapies used for the treatment of benign enlarged prostates. They do not have a role in the treatment of cancer currently, although this is being investigated. They do have some of the side effects noted by you and in the situation of symptoms related to BPH, different options do exist, including drugs like Flomax. I would say in this situation there's really no advantage of Proscar over Avodart or vice versa.

MEMBER QUESTION:
What are the advantages and disadvantages of having a combination of hormone therapy with radiation therapy, as opposed to just radiation therapy alone? What types of patients are good candidates for combination therapy?

OH:
We generally divide patients with localized prostate cancer into three categories of risk -- low, intermediate and high.

• High-risk patients are those with Gleason scores of 8 to 10, prostate-specific antigens (PSAs) over 20 or large tumors on examination called T3 tumors. Such patients should always have hormonal therapy combined with radiation unless there's an absolute reason they cannot receive hormones.
• Intermediate-risk patients are those who have a PSA between 10 and 20, a Gleason score of 7 or a tumor that can be felt with the finger, T2. In this situation a recent study suggested six months of hormones may make radiation better but this remains somewhat controversial. Some people believe that in the intermediate risk, higher doses of radiation may accomplish the same goal.
• Low-risk patients are those with the PSAs under 10, tumors you cannot feel on a prostate exam and a Gleason score of 6 or below. These patients probably do not need hormonal therapy with radiation.

So the high-risk patient should always get hormones, intermediate may benefit from the addition of hormones to radiation and low risk should generally not receive hormones with radiation.

MEMBER QUESTION:
Notwithstanding that it is always an individual decision and there are differences in each patient, what is the current treatment of choice for a 55-year-old male with prostate cancer isolated to the prostate (Gleason of 3 from one of the 10 biopsy sites, PSA of approximately 24 and prostate approximately double the size of normal)?

OH:
This is a difficult question to answer since different options exist in this situation and no studies have proven one type of treatment is superior to another.

Surgery would be considered an option but the patient's PSA would be considered a higher risk feature and make it more likely there may be some more cancer outside the prostate. Hormones combined with radiation therapy would be considered another option.

Other options exist and because there's no single standard of care, this decision is best made by consultation with a multidisciplinary group of physicians, including a urologist, a radiation oncologist and if available, a medical oncologist.

MEMBER QUESTION:
Is surgery still an option if cancer reoccurs after seed implants or radiation therapy?

OH:
Surgery after seeds or external radiation is associated with a higher risk of complications than if it is performed prior to such treatment. It is the subject of a clinical trial that is ongoing nationally.

In most circumstances patients whose cancers were not cured by seed implants or external radiation would not be good candidates for surgery. But, individual circumstances differ and options need to be considered in light of the higher risk of complications.

MEMBER QUESTION:
I have prostate cancer (PC). When it was first diagnosed the biopsy showed one of eight samples had cancer. I am 81 years old. My cancer is T2 and my Gleason score is 3+3=6. I elected to go on "watchful waiting" and hope to outlive the cancer. I go to my doctor two times a year for checkups. Do you think this is a wise choice for me or should I be more aggressive with treatment? I had transurethral resection of the prostate (TURP) right after diagnosis and none of the tissue had any cancer.

OH:
Watchful waiting is considered a reasonable option for patients with lower grade smaller volume cancers. In particular, it's a reasonable option for older patients for whom a slow-growing cancer may not be a potential risk to their lives. Of course, we do not know the optimal patient at this time that does not need any treatment for their cancer. That is why watchful waiting is only one of a list of choices in this type of circumstance.

Your age plus the Gleason score and low volume of cancer would make you a particularly attractive candidate for a watchful-waiting program, since it may take many years, as many as 15 to 20, for such a cancer to be clinically a risk to you. That said, cancers may change over time, so close follow-up on a watchful-waiting program, including frequent examinations of the prostate, PSA testing and occasional rebiopsies of the prostate are likely to allow you to know if this cancer is changing.

MEMBER QUESTION:
Two years ago I had my prostate removed and I have had my PSA tested every four months. My last PSA was 0.04 (less than the required 0.1) How often should I have my PSA tested and what should I do to stop the cancer from returning?

OH:
I think that continuing PSA checks every three to six months in this situation is reasonable. A PSA of 0.04 is still very low after surgery and consistent with cure. However, only time will prove this and if, in fact, the PSA were to continue to rise, then that would be a sign that microscopic residual disease is present.

There is no data currently about whether any treatments given after surgery can definitively prevent recurrence, with the exception of external radiation to the prostate bed. This would be a consideration if your PSA were to continue to rise and if scans did not demonstrate evidence of cancer outside of the prostate bed. Beyond this additional radiation treatment, there still remains very little data about whether treatments such as hormonal therapy, nutritional interventions or other treatments can prevent recurrence.

In your situation I would continue to follow as you are and consider options depending on how fast the PSA is rising, if at all.

MEMBER QUESTION:
My dad had PC, so it may run in the family. I am now 41 years old. What steps should I take to help me avoid prostate cancer?

OH:
Prostate cancer does tend to run in families. The recommendation of the American Cancer Society and the American Urological Association for men such as you, who have a first-degree relative with prostate cancer, is to have a screening PSA test and prostate examination in their early 40s. Since you are now 41, it would be a reasonable issue for you to discuss this with your primary physician.

Regarding prevention of prostate cancer -- little is known about whether any specific nutritional or drug intervention would decrease your chances of getting prostate cancer. However, epidemiological studies have suggested that certain nutritional interventions for instance, might decrease the general risk of getting prostate cancer. These include a low-fat diet, particularly animal fat, moderate exercise, increased uses of tomato-based products which have an antioxidant called licopene in them and decreased use of dairy products, although this remains controversial. Vitamin E and selenium are also possibly associated with a decreased risk of prostate cancer. However this is a subject of a prevention trial currently ongoing in the United States.

There was another prevention study looking at the drug Proscar published several years ago in the New England Journal of Medicine. This study suggested that men who took this drug had a decreased risk (25%) of prostate cancer after seven years. However, the type of cancers that developed during the study period appeared to be of higher Gleason score, namely more aggressive in appearance. This has led many experts to hold off on the recommendation to routinely take a drug such as Proscar for cancer prevention.

In summary, most of the data here would suggest that some dietary and nutritional interventions might decrease the overall risk of prostate cancer but this has not been clearly proven. A PSA test would be a reasonable thing to consider over the next few years for you.

MEMBER QUESTION:
I've read that the best candidates for surgical removal of the prostate are men under 70 years of age. Is the surgery less likely to be effective for men over 70, or more likely to have serious complications? Why are men over 70 less likely to be good candidates for surgical removal?

OH:
In general, men over the age of 70 have an increased risk of complications related to surgeries compared to men under 70. The recommendation of 70 as a general cutoff for surgery stems from two points: The first is that very effective alternatives are available to men of all ages that would represent a very suitable alternative to surgery and the second is the increasing risk of complications in the older men.

That said, many urologists will operate on men over the age of 70 if they are otherwise in good health. But, it should be clear to patients that surgery has not been clearly proven to be superior to treatment such as radiation or seeds in all situations.

MEMBER QUESTION:
At what point in time after removing the prostate, and for the past two years of "excellent" follow-up results, is a person safe from having the cancer again?

OH:
That's a good question. Prostate cancer has a very long natural history. In this regard, that means that it takes many years from the treatment to be certain that the cancer will never recur. Generally, with each passing year, and at 5 and 10 years, a person who has no evidence of recurrence measured after surgery, such as a PSA that's undetectable, should be increasingly confident he's been cured. However, the greatest certainty really comes out after 10 to 15 years of follow-up.

MEMBER QUESTION:
What is your opinion of cryoablation for primary or recurring treatment?

OH:
Cryosurgery has had an up-and-down history in terms of the evidence for its benefit, and like the other treatments for prostate cancer, has never been compared to a treatment such as surgery or seed implants in such a way that we know whether it's better, worse, or the same. Therefore, it's very hard to comment on advantages and disadvantages compared to those treatments.

Generally there has been less data in the use of cryosurgery as primary treatment, but single institution studies have shown this treatment can effectively treat localized prostate cancer. We just don't know if it's as good as or less effective than other options. In the area of recurrent disease, there has been more enthusiasm for cryosurgery as an option. However, these remain relatively small studies of selected patients in a small number of centers around the country.

As discussed earlier in the context of surgical intervention after radiation, there may be a role for cryosurgery in some patients with local recurrence after more standard options such as radical prostatectomy or seed implantation.

MEMBER QUESTION:
I was diagnosed seven years ago. I had been responding well to hormones, despite some of their issues, but my PSAs had risen during my last visit. I am discussing options with my urologist and others who have been where I am. Is the change in how hormones had been helping a sign of changes, and what are my options?

OH:
A rising PSA in the setting of hormonal treatment can be a sign of what we call hormone refractory or resistant disease. This situation requires that a testosterone blood level be checked to be certain that the hormone shots are effectively suppressing testosterone. If this is the case, or if the hormone treatment was surgical castration, then options at this point include the use of secondary hormonal treatments and chemotherapy.

It would be considered premature at this point, in my opinion, to use chemotherapy if the only sign of this refractory cancer is a rising PSA. That said; the goal of treatment here is to try to suppress and delay the cancer from growing in this hormone refractory state.

Secondary hormone treatments include high dose Casodex, ketoconazole, and estrogen type treatments. These are generally best discussed with a medical oncologist, and I might suggest a consultation with a medical oncologist be conducted in the near future to review these choices.

The good news is there is a lot of research going on in this area, in addition to these standard options I mentioned. For instance, a recent study in hormone refractory disease was presented at a prostate cancer meeting in Florida that suggested that a vaccine called Provenge improved survival in patients who received this compared to a placebo. This vaccine is not commercially available and there are ongoing studies, but it points out that promising new treatments are on the horizon.

MEMBER QUESTION:
Can you say with absolute certainty that a biopsy needle will never deposit a cancer cell into healthy tissue as it is withdrawn from a cancerous prostate?

OH:
Of course we can never say with absolute certainty that biopsy procedures don't "spread" cancer. That said, it is highly unlikely that needle biopsies have any impact on promoting cancer spread. Why is this so? Millions of men get biopsies and are diagnosed with cancer that has been completely cured with treatments such as surgery or radiation. If biopsy did have a significant risk of spreading cancer beyond the organ, then one would suspect cure would be unlikely or otherwise compromised.

So in my opinion, I do not believe men should be overly concerned that biopsies spread cancer. In fact, cancers spread themselves, and this is the greatest concern of all.

MEMBER QUESTION:
Can you tell me about Taxotere and its role in helping with prostate cancer?

OH:
Taxotere is a chemotherapy drug that was approved last year for the treatment of hormone refractory prostate cancer. Taxotere given to these most advanced patients allowed them to live longer by 25%. This was a very significant step forward.

Currently research directed toward administering drugs like Taxotere earlier in the patient's course, so we are not waiting for the cancer to metastasize to the bones or to become refractory or resistant to hormones. These studies are ongoing, but we're very hopeful that drugs like Taxotere will help men particularly with high-risk prostate cancer, at diagnosis, to in fact try to improve their cure rates. We know in diseases like breast cancer that using chemotherapy drugs earlier has a greater impact than waiting until the cancer becomes more advanced. We are just starting this process for prostate cancer patients but are very excited about new research building on Taxotere and its success.

MODERATOR:
Before we wrap things up for today, Dr. Oh, do you have any final words for us?

OH:
I'd like to thank everybody and to say that from a research perspective and being a doctor who takes care of prostate cancer patients, I'm extremely excited about what the future holds, but also humbled by the challenges my patients go through.

For early prostate cancer patients our challenge is to understand who should receive treatment and who should not, if treatment is warranted, and what the best treatment is for any single patient.

For patients who are not cured by their initial treatment for prostate cancer we need to come up with better therapies. This is an exciting area of research and I believe we will have important new treatments over the next few years. I would encourage patients in this group of recurrent or advanced disease to participate in clinical trials and to seek out opinions from medical oncologists involved in the care of prostate cancer patients.

I have great optimism for the future and hope our efforts will have a meaningful impact on patients' lives in the near future.

MODERATOR:
Our thanks to William K. Oh, MD, for joining us today. And thanks to you, members, for your great questions. I'm sorry we couldn't get to all of them.

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