3rd annual Sir Peter MacCallum public lecture: your questions answered
3rd annual Sir Peter MacCallum public lecture: your questions answered - Research at Peter Mac
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| Answers to audience questions from the public lecture event on Wednesday 26 October are below. These answers reflect the personal positions of Peter Mac clinical and research experts, but do not reflect the views of the Peter MacCallum Cancer Centre. |
| 1. Are we now in an epidemic of cancers? Or has it always been like this? |
| The majority of cancers occur in older Australians. The absolute numbers are rising due to increasing life expectancy, decreased deaths from cardiovascular disease, and demographic changes associated with the aging of the ‘baby boomers‘ generation. |
| 2. Why can't we just reduce all testosterone in men who are diagnosed with prostate cancer? |
| Reducing testosterone produces side effects such as hot flushes and fatigue and carries the risk of rarer, more serious side effects such as increased risk of heart attacks, strokes and osteoporosis. Studies that espouse the benefits of reducing testosterone are based on more advanced cancers. Therefore, as this approach is based on evidence that addresses both potential benefits and the risk of side effects, reducing testosterone is generally only carried out in high risk or advanced cancer patients. |
| 3. My late wife had brachytherapy for cervical cancer, before developing a bladder cancer which was removed; following a brain cancer in the left lobal area, she passed away. What should I advise my daughters regarding annual check ups? My father had pancreatic cancer and died in 1966; what warning should I give to my sons and grandsons? |
| There is a well-established screening program for cervical cancer using pap smears. Your daughter should discuss this with her general practitioner or nurse. Your sons are at 3-4 times higher risk of developing prostate cancer in their lifetime and should discuss the pros and cons of prostate cancer screening with their GP from the age of 40-45. |
| 4. What does 6 on the Gleason scale mean? |
| The Gleason scale is based on what a pathologist sees under the microscope when examining prostate tissue (either through biopsies or the actual prostate). The score reflects the aggressiveness of the prostate cancer — a score of 6 is a less aggressive cancer, while scores of 8-10 indicate more aggressive cancers. |
| 5. ‘One option for a patient is “watchful waiting” or “active surveillance”.’ How can the progress of prostate cancer be monitored other than through periodical biopsies? |
| There is a slight difference between watchful waiting and active surveillance. Watchful waiting is for older men who are expected to have slow (if any) progress of their disease and who may eventually require treatment to slow up the progress (e.g. with hormonal manipulation). Watchful waiting is monitored with PSA tests and examinations. Active surveillance is usually for younger men who may need curative treatment such as surgery or radiotherapy; these men are monitored more closely with PSA tests, examinations and repeat biopsies every one or two years. |
| 6. Other countries appear to be using photodynamic therapy for cancers other than skin cancers. Is this being considered for prostate cancer at Peter Mac? |
| There is no strong evidence that photodynamic therapy has a significant beneficial effect for the management of prostate cancer. |
| 7. What is meant by ‘staging’ cancer treatment (surgical, radiotherapy, chemotherapy) to ‘coincide with peaks in a patient’s immune cycle’? |
| This is an area of experimental interest in some cancers but there is no significant evidence at this stage that it is of value in prostate cancer treatment. |
| 8. What is the average age of mortality following diagnosis of prostate cancer? |
| Those at most risk of dying from prostate cancer are over the age of 75, similar to many other common cancers. The overall mortality rate from prostate cancer in Australia has dropped by about 30% since PSA testing became more widespread in the early 1990s. Overall, the risk of dying from prostate cancer before aged 75 is 1 in 104; the risk of dying from prostate cancer before age 85 is 1 in 25. |
| 9. Why has it been in the news lately that America is against PSA testing? |
| There were headlines recently when an American group called the US Preventive Services Task Force advised against PSA testing; this same group previously attracted criticism when they advised against mammography for women in their 40s. This has provoked much controversy as many other American groups are in favour of PSA testing when men are fully informed about the pros and cons of the test. Our advice is in-line with Cancer Council Victoria and other information sources : men should discuss the pros and cons of PSA testing with their doctor before making an informed choice on whether or not to be tested. Men should consider having this discussion with their GP when in their 40s if there is a family history of prostate cancer. |
| 10. Are there correlations between the effectiveness of different treatments and the type of prostate cancer? |
| Some prostate cancers are more aggressive than others and some prostate cancers are unfortunately quite advanced at the time of diagnosis. Depending on these factors there are a variety of treatments currently available for prostate cancer, including clinical trials of new drugs for advanced prostate cancer — your specialists will be able to discuss these with you. Surgery and radiotherapy remain the mainstay for the management of early prostate cancer, while some low-risk early prostate cancers do not need active treatment but can be kept under surveillance. At Peter Mac all prostate cancer patients are discussed in a multidisciplinary meeting so that all treatment options can be considered and offered to our patients. |
| 11. What rates of breast cancer incidence in a family will lead to a predisposition to prostate cancer in male members? |
| In families where there are multiple cases of breast cancer and a confirmed genetic fault (mutation) in the BRCA2 gene, the men in these families have a 4.6 times increased risk of developing prostate cancer by the age of 70 years compared to men in the general population. |
| 12. Is there evidence of an increased likelihood of prostate cancer in families with a high incidence of various sorts of cancer, not just breast cancer? |
| Regarding family history of cancer, a previous history of prostate cancer in the family remains the most significant risk factor. A history of breast and/or ovarian cancer may increase risk due to the presence of genetic factors and this is an area of research interest at Peter Mac. No other cancer types correlate as strongly with prostate cancer. |
| 13. What is the probability of prostate cancer returning, after a successful prostatectomy? And if the cancer returns, what can be done? |
| The risk of recurrence depends on a number of factors, most notably the stage and grade of the cancer when the prostate specimen is analysed following radical prostatectomy. Overall, the risk of biochemical recurrence (PSA becoming detectable) is about 20% at five years but for less aggressive cancers — such as cancer confined to the prostate rather than penetrating through the capsule — this can be much lower following successful surgery. A number of further treatment options are available, including radiotherapy and hormone treatment. Overall, the 15–year prostate cancer-specific survival following radical prostatectomy is very good at 93% with about 7% of men requiring adjuvant radiotherapy and 9% requiring hormone treatment over that period. |
| 14. A man with a PSA of 4.9 is diagnosed with prostate cancer at the age of 64 and surgery reveals that the tumour comprises 50 per cent of the prostate. He then has extensive radiotherapy, but the PSA continues to more than double in consecutive three–month periods. He then has six months of hormone treatment via injected pellet and the PSA reduces. What does this mean? Is the cancer still there on his bones waiting to return if he stops the hormone treatment? |
| Yes, the presence of a significant level of PSA following removal of the prostate means that some prostate cancer is likely to be present elsewhere in the body. The reduction in PSA suggests that most of the cancer cells are dependant on testosterone and that therefore the hormone injections are controlling the cancer quite well. The cancer cells are likely to have stopped growing and some will have died. There is still likely to be some cells that are still alive and will potentially start growing if the hormone treatment is stopped or they become resistant to it. However the hormone treatment can keep many of these under control in the long-term. |
| 15. Given that the prostate enlarges with age, are the chances of prostate cancer increased with an already ‘grossly enlarged’ prostate diagnosed at age 73 (PSA 3.6)? |
| The most important determinant of the likelihood of prostate cancer being present in this situation is not the already enlarged prostate but the age of the patient. Benign (non-cancerous) enlargement of the prostate is not a risk factor for prostate cancer but both conditions may co-exist. Prostate cancer becomes more common as men get older and your doctors will be able to advise you about the risk of prostate cancer in your circumstance and to discuss whether you should be referred to a specialist. |
| 16. I’ve had my prostate out and my radiation reading has gone down, what percentage chance is there that it will go up again? Does smoking have an effect? |
| There are no strong links between smoking and prostate cancer. The risk of your PSA rising in your circumstance depends on a number of factors including the stage and grade of your prostate cancer at diagnosis — your specialist will be able to provide further advice. |
| 17. What happens if the prostate is removed? |
| There are a number of consequences of having your prostate removed which can be discussed in detail during a consultation with your doctor or specialist. The principle function of the prostate is to facilitate ejaculation and following removal of the prostate, ejaculation is no longer possible. However sexual and erectile function may still be possible as the nerve supply to the penis may be preserved. |
| 18. What is the survival rate of cancer after a radical prostatectomy, radiation therapy and two and a half years of hormone treatment, for (stage) T4 advanced prostate cancer? |
| Overall, the five year survival rate in men with locally advanced prostate cancer following radical prostatectomy and radiotherapy and/or hormone treatment is about 70 per cent. |
| 19. What are the short/long-term effects of radiation therapy, particularly after prostatectomy, and radiation with markers for cancer on edge of prostate? |
| With external beam radiation therapy, whether directed at the entire prostate or on specific targets after surgical removal, there will always be some radiation dose that deposits in nearby normal tissues even with the high precision of modern equipment. This means that in the short term, there will be irritation of the lower part of the bladder and rectum which is usually felt as a stronger urge to go to the toilet more often than usual. This irritation usually subsides with six weeks of completion of treatment. When this irritation creates scar tissue, these symptoms can remain present in the long term for a small number of men, but this rarely requires any treatment. Similarly, the scar tissue can crack and bleed (in around five per cent of men), but is rarely a significant health issue and can be successfully treated in most cases if needed. Radiation therapy will have an impact on erectile function in most men, especially if they have less than excellent function to begin with. Radiation can also cause genetic damage to surrounding healthy tissue which can induce new cancers to form, but thankfully these instances are very rare (one study suggests around 1 in 300 men will get a second cancer related to radiation of the prostate), usually take well over 10 years to develop and are usually seen as a slightly increased risk of more common cancers such as those of the bowel and bladder. Patients should follow the recommendations of their GPs to address this long term risk. |
| 20. With regard to penile rehabilitation, what are the best practice guidelines? i.e. medicine, penis injections, vacuum pumps, masturbation, or a combination of some/all of the above? |
| A combination of all of these is usually employed, starting with medications and adding in other elements depending on response. Penile rehabilitation is an important focus for recovery following robotic radical prostatectomy and our specialist nurses have particular expertise in this area. |
| 21. Is prevention still better than cure? When will Peter Mac start partnering with VicHealth/CCV to invest in prevention research? |
| Prevention has been the focus of a number of very large studies in recent years. Vitamin supplements and certain medications have been investigated and at present, there is no strong consensus that any of these strategies should be routinely employed to prevent the development of prostate cancer. |
| 22. Can the genome test be covered by Medicare for males aged over 40 with a family history of prostate cancer? |
| At present, screening the whole genome of patients is performed in the research laboratory. This technology is not performed by a clinical service; therefore, there is no Medicare cover. |
| 24. I have been on a Ph III (double blind) clinical trial for a new chemotherapy. After two months my oncologist took me off the trial; my cancer was progressing, I had most likely been on a placebo. Just recently I have been denied to be part of a clinical trial/early access for the same product because of the earlier Ph III trial participation — is this fair? |
| Note: We are unable to comment on individual situations without knowledge of a patient’s entire medical history. |
| Clinical trials are a very important part of cancer research and often offer patients an opportunity to access drugs otherwise not available in Australia. We are very grateful when patients consent to take part in clinical trials although many of these are randomised and placebo-controlled, meaning that patients may not get the active compound. However if that compound subsequently becomes more widely available then patients can usually access this. Also, there are a number of exciting new drugs now available in clinical trials and patients who have already participated in trails (especially if they received placebo) may still be eligible for these trials. |
| 25. Is there cooperation between various cancer research groups in Australia? |
| The Australian cancer research community is a very strong collaborative community, with many projects underway across hospitals and research institutes Australia-wide. For example, cancer researchers at Peter Mac are involved with basic and clinical projects with: |
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Our researchers and clinicians also lead and contribute to national and international clinical and translational collaborative research studies, including with the Australian Ovarian Cancer Study, the Australasian Sarcoma Study Group, the Melbourne Melanoma Project, kConFab, Lifepool, Trans-Tasman Radiation Oncology Group (TROG), the Australasian Leukaemia and Lymphoma Group, and the Victorian Public Hospital Robotic Program. |
