Sobering Up; Late Metastasis
This is a distressing article from Nature about the (rare) possibility of very late recurrences of breast cancer. Frankly, I debated with myself about sharing it, but I am a big believer in knowledge is power, and I assume that anyone reading this blog feels similarly--or can choose to skip today's. Here is the summary statement and the bottom line: The longer you go without a recurrence, the more likely it is that you will stay well. However, there is always a chance that breast cancer will recur, and it can happen years after the initial diagnosis.
Scientists and oncologists are struggling with this reality and trying to figure out why it happens. What changes so that cancer cells, that have been lying dormant for a long time, suddenly wake up and cause big trouble? We know that the practice of keeping women who are ER positive on endocrine/hormonal treatments for years may result in an increase in late recurrences. That means: women who take tamoxifen and/or an AI for ten years or so occasionally (and this is pretty rare, do not panic) have a recurrence after, say, 12 or 13 years--presumably after those treatments have ended, and the cancer cells have had a chance to regroup. The positive spin is that these same women likely would have had a recurrence years earlier without the endocrine treatment but that is little comfort in the midst of the crisis.
Here is the beginning of the article and then a link to read more:
Ann Chambers has a series of graphs tacked up in her office at the London Regional Cancer Program in Canada, where she is an oncologist. "I stare at them all the time," she says.
These charts are assembled from more than 60 years of data gathered at the MD Anderson Cancer Center in Houston, Texas, and showhow the ten-year survival curves for local and metastatic breast cancer have changed over the decades (see 'The hard facts', page S50). The picture they paint of breast cancer, Chambers says, has regions of darkness and light.
On the one hand, the overall survival rate of patients with breast cancer has vastly improved. Sixty years ago, only a quarter of patients were alive ten years after being diagnosed; now, that figure exceeds three-quarters. On the other hand, for patients whose tumour has metastasized - spread to distant sites outside the breast - at the time of diagnosis, the picture remains dismal. Even now, a patient with metastatic breast cancer has only a 22% chance of surviving more than ten years.
The graph that troubles Chambers most, however, is the one for patients with local breast cancer who show no evidence of metastasis at diagnosis. Decade after decade, the survival curves for these patient cohorts decline over time, with the current ten-year survival rate at 86%. The implication is that, despite appearing free of disease, "there are hidden tumour cells in these women", says Chambers.
These cells are lurking in a state of suspended animation. It might be a rare event; however, even 25 years after diagnosis, these dormant cells can reawaken, growing into a full-blown metastasis and ultimately killing a patient who was once considered to be cured.