Breast Cancer and the Five Year Mark: The Limitations of Statistics

Patient Expert

Everywhere I turn, I see news about marvelous advances in the fight against breast cancer.   Nancy Brinker, founder of Susan G. Komen for the Cure, writes on the Komen website, "We have come a long way in our fight. Twenty-five years ago, when breast cancer was diagnosed before it spread beyond the breast, the five-year survival rate was just 74 percent. Today, it is 98 percent."

The National Cancer Institute (NCI) data for all breast cancers is similarly optimistic showing a 75 percent five-year survival rate 35 years ago compared to almost 90 percent now.   To read these optimistic figures one would think that breast cancer is a highly curable disease -- no big deal.

Yet every month I write condolence notes to the families of women I've come to love and admire on cancer mailing lists to which I belong.   How do we account for the difference between my reality and the statistics?

Part of it is the frequency of the disease. The NCI estimates that in 2008, 182,460 women and 1,990 men will be diagnosed, and 40,480 women and 450 men will die of breast cancer.   With so many people being diagnosed even a 90% survival rate allows for a lot of deaths.

However, the use of the five-year survival number may be very misleading these days.   New treatment methods keep cancer under control longer, but cancer is a sneaky disease.   One reason the statistics are improving is that mammograms are finding more early stage cancers.  Take my friend Janet, for example.   When I was diagnosed, she was an encouraging mentor to me: a ten-year survivor.   Her Stage I breast cancer was treated with surgery, and the surgeon told her she didn't need any follow-up treatment.

She moved on with her life until about 12 years after her original diagnosis when a nagging cough sent her to the doctor.   For the next three years she inspired everyone by showing up for work every day despite her treatments for a metastasis in her chest.   Janet, dead about 13 years after her original early-stage diagnosis, doesn't show up in the five-year mortality rates.

My mother's sister, Thelma Robinson, doesn't show up in those numbers either.   She was diagnosed with breast cancer and lymph node involvement in about 1990.   She chose to be treated with surgery and radiation, and passed that magic five-year mark only to find in 1998 that her cancer had returned.   This time it was throughout her body, and she lived only a few months after the metastasis was confirmed.

My oncologist tells me that the longest he has personally seen a woman go before a breast cancer recurrence is 21 years.   Using five years to measure success in the fight against a slow growing cancer may be giving us a false picture of progress.

Even with aggressive cancers like inflammatory breast cancer (IBC), the five-year number may be misleading.   In the ten years that I've participated in the IBC on-line community, the number of women with Stage IV cancers who fight on for years while in treatment has multiplied dramatically.   A typical scenario is diagnosis, eight to twelve months in treatment, a couple of years No Evidence of Disease (NED), recurrence, and then several years of trying a series of chemos and other treatments until mailing list members get the sad news of our friend's death.   These women also make the five-year survival list.

I am concerned that the glowing statistics may encourage someone to delay checking out symptoms thinking breast cancer is easy to cure, no big deal.   I've noticed that some people are almost nonchalant about a breast cancer diagnosis of a friend or colleague.   "Breast cancer is so treatable these days.   She'll be fine."

I don't want to denigrate the substantial progress medicine has made.   A 90 percent five-year survival rate is dramatically better than 75 percent.   Those five years can give families time to make memories they will cherish forever.

Breast cancer survivors can rejoice in improved medical treatments.   We also need to be diligent about our follow-up care even years after our diagnosis if we want to beat this sneaky disease.