The American Society of Clinical Oncology (ASCO) annual meeting is taking place in Orlando, Florida, May 29 â€“ June 2, 2009. This meeting provides an opportunity for cancer researchers, doctors, and advocates to attend educational sessions as well as learn about advances in cancer science.The first day was filled with educational sessions. It was a bit disappointing, as there was not that much new information. Here are the highlights:
This session addressed osteoporosis and its treatment, particularly as it overlaps with cancer. I had high hopes, which were quickly dashed, as it was a standard talk, with nothing new. I was particularly struck by the fact that we are still treating a test (bone density) and not using fractures as an end point when we discuss osteoporosis treatment with a bisphosphonate, and its effectiveness.
The data show that women who take aromatase inhibitors lose bone, but that it returns when they stop the drugs. Do we really have to give them bisphosphonates to prevent the loss if it is temporary, particularly if we donâ€™t know the long-term consequences of this drug? Thatâ€™s the question I walked away with, and one that I wish had been addressed.
More intriguing were the findings from a study that looked at premenopausal women who were put into temporary menopause with goserelin [brand name Zoladex] and then randomized to either tamoxifen or an aromatase inhibitor followed by another randomization, to a bisphosphonate or a placebo. Apart from the fact that this is a lot of drugs for a cancer that this study showed had a 98% survival rate, the results were interesting in what they teach us about this disease.
First, there was no difference between the aromatase inhibitor and tamoxifen, probably because the premenopausal women had been put into temporary menopause. Second, and more interesting, was the finding that the disease-free survival was better in either group when a bisphosphonate was added. This changes the picture, as it suggests that we should be giving bisphosphonates as cancer treatment rather than to treat the bone density test. Why would we get his result? I donâ€™t think we know. Could it be that the bisphosphonates have an effect not just on osteoclasts (the bone cells that break down bone) but the stroma (the connective tissue cells)? This is interesting and something I will continue to ponder.
Really not much new here other than the fact that you can still get lymphedema and/or numbness after a sentinel node biopsy. There is still much controversy about whether a sentinel node biopsy should be done in cases of DCIS, although it doesnâ€™t appear to add much other than side effects. There was also no consensus on whether a sentinel node biopsy should be done if there is a recurrence of the DCIS.
Magnetic Resonance Imaging (MRI)
This session reviewed the data of the use of MRI in women diagnosed with breast cancer. Bottom line: MRI can be used to monitor the size of breast cancers that are treated first with chemotherapy, IF they are the right kind of cancer. It doesnâ€™t work on all cancers, and has both false positives and negatives.
But what about MRI in women who are newly diagnosed? An excellent review of the data by Dr. Houssami, concluded that MRI does not add an incremental benefit in the treatment of the disease. Part of the problem is that it finds two benign lesions for every cancer. It also leads to conversion to more extensive surgery 11% of the time. However, half of the time this is because of a false positive result. There also is no evidence that pre-operative MRI affects clinical outcome.
What about using MRI pre-operatively to find cancer in the other breast? The data show that preoperative in 9.3% of the women MRI found a suspicious lesion in the other breast, but only half of these lesions were actually cancer. MRI detects mostly â€œgoodâ€ cancers and it is certainly not clear whether they are clinically significant.
Finally, there was a review of whether preoperative MRI leads to a lower local recurrence rate. In other words: Does MRI make the surgery better so that the woman will not have a recurrence in her breast? The answer: The recurrence rate after breast conservation is very low, and MRI does not improve it. I fully agree with the conclusion: preoperative MRI adds little to preoperative planning and does not improve the outcomes of local treatment. I am sure it is not cost effective (study not yet done) and we really have to stop routinely using this expensive imaging tool.
Saturday morning found me in another educational session, this one on vitamin D. The conclusion was that this topic was complex and that it was not clear that low vitamin D levels were related to breast cancer risk apart from physical activity and BMI. There is also data that you can have too much vitamin D; as with everything it is a U-shaped curve with problems at both ends of the spectrum.
The session confirmed my suspicion that the hype about Vitamin D is premature. The best thing we can do to prevent breast cancer is exercise, but maybe doing it outdoors will give double benefits!