Prostate Cancer: Important News for Patients

Prostate Cancer: Important News for Patients with Eric Small, MD, Chat Transcript
Friday, February 24, 2006 2:00 – 3:00 PM ET
Moderator: On behalf of the American Society of Clinical Oncology (ASCO), welcome to the Cancer.Net Ask the ASCO Expert chat on Prostate Cancer: Important News for Patients, a live question-and-answer session hosted by Eric Small, MD.

During this hour, Dr. Small will answer as many questions as possible. Due to an increasing number of chat participants and number of questions submitted for each chat event, time simply does not allow us to address all of your questions, and we encourage you to consult your doctor and cancer care team.

Some questions may be adapted so that Dr. Small's answers can help as many people as possible.

Dr. Small will take questions from 2:00 – 3:00 PM ET. As you prepare your questions, please keep in mind that Dr. Small is unable to give individual medical advice in this setting, nor is he able to address questions that include information specific to one person's medical profile.

The information presented here is for informational and educational purposes only and is not intended to substitute the professional medical advice or treatment recommendations provided by your doctor.

This forum is neither intended nor appropriate to serve as a means of obtaining a second opinion on cancer diagnosis or treatment. In response to questions about specific drugs, Dr. Small's comments will focus only on the state of current research and clinical trials.

It is advised that you do not delay seeking professional medical advice based on any information received during this chat event.

The chat is governed by all terms and conditions of the Cancer.Net website. Participation in this chat event means that you fully understand and agree to abide by the terms and conditions of the Cancer.Net website.

Good afternoon and welcome. Thank you for joining us. Dr. Small will now begin taking questions.

Eric Small, MD, is currently a Professor in Residence of Medicine and Urology, Co-Director of the Urologic Oncology Program, and Head of Urologic Medical Oncology in the Division of Hematology/Oncology at the University of California at San Francisco.

He has published numerous articles on the treatment of prostate cancer, and is currently the Chair of the Genito-Urinary Committee at Cancer and Leukemia Group B (CALGB).

Dr. Small, thank you for taking the time to join us today.

Dr. Small: Good afternoon. I'm joining you from the 2006 Prostate Cancer Symposium, where breaking news on the prevention, diagnosis, and treatment of prostate cancer is being issued.

I am happy to take your questions now.

jfh: Dr. Small, could you say a few words about the current state of the art for imaging or other techniques to gauge the characteristics of a case of prostate cancer?

Dr. Small: Imaging today mostly gives us information on the extent of cancer, less so on the characteristics of a particular tumor. However, there are investigational imaging technologies like endorectal MRI spectroscopy, which provides information on the metabolic activity of the cancer.

In the future, this may help us to differentiate between different levels of aggressiveness.

Guest119: I had a prostatectomy in February 2005 and we found out that the cancer has metastasized around the prostate bed and lymph nodes. What treatments are most effective for prostate cancer of this sort?

Dr. Small: The standard of care of prostate cancer that involves the lymph nodes is hormonal therapy. There is still considerable debate as to whether to add radiation therapy to the prostate bed and pelvis. We have information from a clinical trial for patients who are getting initial radiation therapy before prostatectomy, and in these patients, if they had a high likelihood of having lymph node involvement, the use of combined hormones and pelvic radiation seem to be a benefit.

We extrapolate from these data for situations like yours.

Guest107: Do you believe men should be encouraged to have PSA and DRE examinations for possible prostate cancer detection upon reaching a certain age?

Dr. Small: It is my belief that all men at risk for developing prostate cancer be screened with both prostate-specific antigen (PSA) and digital rectal examination (DRE). Men at very high risk (family history or African Americans) should be screened beginning at age 40.

Others should be screened beginning at age 50. It is worth pointing out that not all agencies are in agreement with screening. However, some, including the American Cancer Society, believe that prostate cancer screening is important.

Guest97: Are sporadic chills and high fever common side effects of hormone therapy?

Dr. Small: Hormone therapy is associated with many side effects, although most patients only have a few of them. A fairly common side effect is the development of hot flashes, which can be associated with sweating and the sense of a fever. I'm not sure that actual fevers have been described with hormones. You may wish to speak with your doctor about that.

The hot flashes that patients experience can be treated if necessary, and there are a variety of medications that are useful for them, including megestrol (Megace) and venlafaxine (Effexor).

Guest267: What are the best treatment options for hormone-refractory prostate cancer?

Dr. Small: Hormone-refractory prostate cancer (HRPC) is defined as prostate cancer that is growing despite standard hormone therapy. It used to be thought that after hormones, you simply went on to chemotherapy. However, now we appreciate that there is a gray zone between front-line hormones and chemotherapy.

We frequently encourage a clinical trial of a secondary hormonal manipulation before moving to chemotherapy. These kinds of treatments include additional anti-androgens, such as bicalutamide (Casodex), nilutamide (Nilandron), or ketoconazole (Nizoral). After those options are explored, chemotherapy can be considered.

However, many patients with HRPC may not have metastases, and for those patients, holding off on chemotherapy is reasonable. Finally, don't forget about clinical trials in this setting. There are a lot of exciting agents being tested.

Guest142: How effective is intermittent hormone therapy as treatment for prostate cancer?

Dr. Small: Intermittent hormone therapy refers to the use of hormonal therapy for a fixed period of time, after which it is discontinued. Typically, it is used in patients who have a climbing PSA after prostatectomy and radiation therapy, less so in patients with metastatic disease.

What we typically do is treat patients for one year with hormones, using both leuprolide (Lupron) and bicalutamide, and then stop both agents. We resume both agents once the PSA climbs to a pre-determined level, generally 50% of the prior PSA. By so doing, patients generally can be on a year and off a year.

What we know about this approach is that when patients resume therapy, PSA goes back down, patients can cycle on and off therapy, and that this works for prolonged periods of time. In our hands, the average duration now exceeds seven years. Whether this is better than, equal than, or worse than using hormones continually, is not known.

Guest169: My radiation oncologist suggests a combination of limited hormone therapy (two injections) with adjuvant radiation therapy to treat my prostate cancer. I had a radical prostatectomy (Gleason 8 with seminal vesicle invasion and positive surgical margins). My lymph nodes are clear and my PSA is now less than .01. Could you tell me more about the benefits of adjuvant radiation therapy and hormone therapy combined? Are there any studies on this course of treatment?

Dr. Small: The issue of adding adjuvant radiation therapy depends on risk of relapse. The most important question that we ask has to do with when relapse is likely—whether locally (in the area of the prostate), regionally (in lymph nodes), or systemically (elsewhere in the body).

Features predictive of local recurrence include positive surgical margins, and those patients generally need prostate bed radiation. Features predictive of more regional metastases (lymph nodes) include high Gleason score, seminal vesicle involvement, and a rapidly climbing PSA before surgery.

Those patients typically benefit from both prostate and pelvis radiation. Finally, those patients with a high Gleason score, a PSA that doesn't normalize after surgery, and a rapidly climbing PSA are more likely to have systemic disease, and should be treated with hormonal therapy.

Whether using hormones with radiation therapy is important depends on the cancer. In general, the use of short-term hormonal therapy does make the radiation therapy more effective, provided it is given before and during the radiation therapy. We refer to this as 2 + 2 therapy, meaning two months of hormones before radiation therapy, and two months during and after radiation therapy.

Patients who have high-risk disease typically will need additional hormones after the 2 + 2 format.

Moderator: Transcripts of today's chat will be available February 27, 2006, on Cancer.Net by 12:00 PM ET. More information about receiving transcripts will be provided at the end of the chat.

Guest446: What percentage of patients (I was Gleason 7, PSA 6.7) become hormone refractory?

Dr. Small: Any patient who goes on long-term hormone therapy can become hormone resistant. While it used to be thought that the earlier you start hormones, the earlier you became hormone resistant, that may not be the case, and it certainly is not a reason to not use hormones when required.

If your cancer relapses, and you require hormone therapy, the average response duration to hormones for patients with a climbing PSA after radical prostatectomy probably exceeds 10 years.

Guest471: Are there any known herbs that inhibit the progression of prostate cancer?

Dr. Small: The short answer to this question is no. However, there are many natural products that have the potential to prevent prostate cancer and these include possibly, selenium, lycopene, vitamin E, soy protein, and possibly low-fat diets. Whether these interventions slow the progression of prostate cancer once you have it is not known.

It's also important to know that many times botanical products or herbs can have significant interaction and potentially dangerous side effects, when taken in combination with other medication, so it's really important to let your health-care provider know of all the products you are taking.

I generally don't have any objection to herbal products being taken, provided the patient and I have had a chance to talk about it to make sure it's safe.

Guest230: I am 64 years old and was diagnosed with prostate cancer. What course of treatment do you recommend for a patient with a PSA of 4.5 and a Gleason level of 6?

Dr. Small: The decision for what kind of therapy to have is very complex, particularly for a patient like you that has a relatively good risk cancer. Watchful waiting may be appropriate for some patients, where the operable word is "watchful." Watchful waiting patients should undergo frequent PSA testing as well as imaging of the prostate with ultrasound or MRI, and potentially even annual biopsy.

Other treatment options include radical prostatectomy and radiation therapy, including seeds or external-beam radiation. The key is to take your time learning about the treatment options because immediate therapy is not required. I would strongly urge you to speak with a urologist as well as a radiation oncologist and a medical oncologist with experience in prostate cancer to get an overview of your options.

The good news is that you are likely to do extremely well, no matter which therapy you choose.

Guest501: Two years ago, I was diagnosed with prostate cancer and had surgery followed by radiation therapy (Gleason with marginal involvement). Eleven months ago, my PSA was steady at .02 and then gradually went to .09. When is it time to begin hormone therapy?

Dr. Small: A climbing PSA after radical prostatectomy is one of the most common events that we see. The first thing to know is not all patients with a climbing PSA will get into trouble from their prostate cancer, so not everyone needs therapy.

The clinical features that have been observed to predict the likelihood of a cancer metastasizing include the Gleason score, the length of time from prostatectomy to detectable PSA, and most importantly, the PSA rate of climb, which we refer to as PSA doubling time (PSA DT).

The first thing we need to do is to get a sense of rate of climb of your PSA. I generally recommend a taking of the PSA, every two to three months, at least two to three times. Sometimes, we recommend repeating a transrectal ultrasound to see if there is local recurrence. The time to begin hormone therapy is generally driven by the PSA doubling time.

For patients with a PSA DT of less than three months (let me clarify that this is a calculated PSA DT, so it's not a required program to calculate it), immediate hormonal therapy is warranted.

For patients with PSA DT greater than 12 months, it may be reasonable to observe. Between three and 12 months is a gray zone, where we have to make individual decisions with patients. Again, this is a great area in which to consider investigational agents in clinical trials, especially if your PSA DT is more than three to six months.

Guest219: Are there any promising prostate vaccines being developed, and what are the chances of them being approved soon?

Dr. Small: Immunotherapy for prostate cancer is a really exciting frontier that I think holds tremendous promise. There are currently no approved immunotherapies or vaccines for prostate cancer, but many are being evaluated in clinical trials. What we know from these trials is that many of these agents are able to elicit a strong immune response and there are hints of having efficacy against prostate cancer.

Most of these agents are being developed for patients with metastatic hormone refractory prostate cancer. It is my belief that the chances of some of these agents being approved soon is good, but almost certainly the product label will be for patients with metastatic, HRPC.

When and how these agents can be used for earlier stages of prostate cancer remains to be seen.

Guest159: Can you please explain how hormone therapy loses its effectiveness in treating prostate cancer over time? Once prostate cancer becomes androgen-independent, what happens and how is it treated?

Dr. Small: We believe that hormone resistance develops because prostate cancer cells change and become super sensitive to the male hormone, testosterone. Even when you eliminate testosterone with hormones like leuprolide, the small amount of hormone that remains can make the prostate cancer cells grow. That is why we frequently use secondary hormonal manipulations as the first step in the treatment of HRPC.

Eventually, however, even secondary hormones stop working, and this is a situation where either investigational therapy or chemotherapy can be used.

I'd like to make three comments about the misconceptions of chemotherapy. First, some people say that chemotherapy doesn't work for prostate cancer—nothing could be further from the truth. Chemotherapy may be the most active treatment we have for HRPC.

Second, some people say that chemotherapy will just make you sick. Again, that is not true. Many patients feel better on chemotherapy because their cancer is brought under control. Getting chemotherapy is not like getting water, but the therapies that are used for prostate cancer and the antidotes that we have, make the experience tolerable.

The third misconception is that chemotherapy should be used only as a last-ditch effort, and that's also not true. In prostate cancer, as in other cancers, the less cancer there is on board, the better the chemotherapy works. Using chemotherapy somewhat earlier in the course of disease is reasonable. The standard chemotherapy for HRPC is docetaxel (Taxotere), although many trials are investigating the addition of novel agents to docetaxel.

Guest309: Dr. Small, I am about to begin treatment for prostate cancer. Some of the information I have read mentions male menopause. Can you explain this?

Dr. Small: So-called male menopause is associated with the use of hormone therapy. When we use hormone therapy for prostate cancer, we drop the levels of the male hormone testosterone, because testosterone feeds the cancer. This results in a symptom complex, which can include hot flashes (that we discussed earlier), fatigue, weight gain, muscle loss, thinning of the bones, anemia, loss of libido (sex drive), and loss of erectile function.

Not all patients have all side effects. Around 10% to 15% of patients will have severe side effects, and 10% to 15% will have mild side effects, with about 70% of patients in the middle.

I don't have the time to go into the treatment for each of these side effects, but it's really important that you specifically and explicitly discuss these with your doctor, and not just assume that they are inevitable.

Moderator: The chat is now ending. Thank you for your thoughtful questions.

We hope this discussion has been valuable, and we regret not being able to answer every question. We want to thank Dr. Small for lending us his time and expertise.

TRANSCRIPTS: The full text of today's chat will be available on Cancer.Net (www.cancer.net) February 27, 2006, by 12:00 PM ET. To receive a copy of the transcript by e-mail, please send a message to contactus@cancer.net.

SAVE THE DATE: Please join Cancer.Net for a live chat about Cancer and Aging America: Valuable Information for Patients and Loved Ones on March 10, 2006, from 2:00 – 3:00 PM ET.

The featured expert is Lodovico Balducci, MD, of the H. Lee Moffitt Cancer Center & Research Institute, University of South Florida.

March Q&A: In March 2006, visit Cancer.Net for a question-and-answer (Q&A) forum on Preventing, Screening, and Treating Colon Cancer.

The featured expert is Robert Mayer, MD, of the Dana-Farber Cancer Institute.

The chat room is now closed. Thanks again for joining us.

More Information

Cancer.Net Guide to Prostate Cancer

Cancer.Net Feature: Highlights From the 2006 Prostate Cancer Symposium

Last Updated: February 24, 2006