What is Metastasis?


In Sept. 2000, after eight years of remission from my Stage IIIB status, I metastasized. My mother must have been doing some research, because one day she said, “Diana, there is no Stage V . . .” That’s right. Supposedly, Stage IV breast cancer is terminal, advanced, end stage. All the words you don’t want to hear. However, with every new advancement and discovery that comes along, every effective treatment that stabilizes its spread, there is more and more likelihood that we will someday be looking at metastatic breast cancer as a chronic illness, somewhat like diabetes. While there may be respites between regimes of treatment, the Stage IV patient today can count on being in treatment for the rest of her (or his) life. And that could be anywhere from 6 months to 6 years . . . or 12 years!


Stage IV is metastasis, or spread to other parts of the body. What causes metastasis? The spread of breast cancer begins with the presence of cancer cells in the lymph system and having a number of positive lymph nodes at the time of initial diagnosis is a good indicator that metastasis is possible, even beyond 5 years down the road (5 years clear is the figure most go by to determine “remission.”) Anyone can metastasize, but usually it is someone who was Stage II or III with positive lymph node involvement in the primary diagnosis. Breast Cancer spreads to the bones, lungs, liver and brain. A biopsy of any tumor in these areas will show it to be comprised of breast cancer cells. In the vernacular, we say we have “mets to the bones” etc.

The battle involves keeping the cancer cells “down” and preventing them from spreading, but metastasis can be very hard to control as errant cells spread rapidly, with new tumors popping up increasingly. Surgery is not usually performed on this type of tumor, instead, we try to shrink them with hormone therapy, chemotherapy and radiation. In this site and on our list we are always interested in reading about new approaches — vaccines and drugs that cut off the blood supply to tumors, drugs that create anti-angiogenesis, etc.


“Nearly 25 percent of breast cancers metastasize first to the bone, and most others eventually show some bone involvement. The skeleton is a site of symptomatic disease in something like 75-85 percent of patients who metastasize.”


“Sixty to 70 percent of patients who die of breast cancer eventually have it in their lungs. The lungs are the only site of metastasis in about 21 percent of cases.”


“Oncologists often consider metastases to organs of the abdomen, especially the liver, the most serious of prognostic signs. After bones and lung, the liver is the third most common metastatic site, presenting as the first recurrence in about 25 percent of cases and eventually present in about two-thirds of women with metastatic disease.”


“Older studies consistently reported that symptomatic brain metastases occurred in approximately 10-15 percent of patients with metastatic breast cancer, but according to some research, the incidence of brain mets appears to be increasing in metastatic breast cancer because the disease can often be controlled for a long time elsewhere in the body, thus giving brain mets, usually a fairly late metastatic site, more time to emerge.”

“The SEER database, maintained by the NCI and a compilation of cancer registries that represents over 20% of the US population, says that of all women diagnosed in 1976, over 48% died of their breast cancer. So that’s nearly half whose cancer eventually metastasized. With more modern treatments and early detection, most current estimates of mortality from breast cancer run anywhere from 25% to 35%, but of course we won’t know for 20+ years how many women diagnosed this year will develop recurrence and die of the disease.”

(Thanks to Musa Mayer, author of “Advanced Breast Cancer: A Guide to Living with Metastatic Disease” [O’Reilly, 1998] for providing these statistics. For more info and resources, see