Diagnosis 2.0

“Patients with multifocal DCIS with microinvasion have a five-year actuarial disease-free survival of 78% compared to 98% in patients with simple DCIS.” Ductal Carcinoma In Situ of the Breast

I am the fourth woman diagnosed with breast cancer on my mother’s side of the family in the past thirty years. Both my great-grandmother and my grandmother’s sister died from metastatic invasive breast cancer. When cancer runs in families, it tends to show up earlier with each successive generation. My cousin was diagnosed with exactly the same cancer as me (multifocal DCIS, comedo carcinoma, Grade 3 with a focus of microinvasion), at precisely the same age as me (I’ll never tell).

My cousin had the same surgery as me (bilateral mastectomy), but unlike me, she did chemo and tomoxifin. My Rx post-surgery was “no further treatment”. I am getting a second opinion about my breast cancer case. If you’re an American, you may be shaking your head right now, and thinking, “What’s the big deal about a second opinion?” Well, in Canada, it’s not common to get a second opinion, and the medical system is not set up to facilitate getting a second opinion.

I have never been able to rest easy with the discrepancy between the finding of microinvasion at the time of my biopsy, and the lack of a finding of invasion in the pathology analysis after my mastectomy. There are multiple possibilities. It is possible that there was a single focus of microinvasion in the DCIS at the time of the biopsy, and that the biopsy itself removed that microinvasive section of cancer cells. It is also possible that the post-surgical pathology missed the invasive component. Another option is that the biopsy pathologist was mistaken about an invasive component. The difference matters, because there are implications for treatment.

The basic question that needs to be answered with a reasonable degree of confidence is, “Did the cancer (DCIS), prior to the surgery, already progress to the point where some of the various tumour segments included invasive cancer cells that could have travelled beyond the confines of the ducts?”

Certainty in this matter of the diagnosis is not on the cards, because all of the methods for the identification of the kind and grade of cancer cells, and the degree or not of invasion, involve probabilistic techniques. No pathologist has the time to look at every cell, nor does the technology to do so even exist. So what pathologists do is based on a cost/benefit ratio acceptable to most parties, that goes something like, “If I slice up the tissue and make slides that I examine carefully from ten or so of the possible thousands of slices, then I will have a representative sample of the total population of material that could be examined.” And there are disagreements, of course, to pile on to what statisticians call, “standard error of measurement”. So if your life depends on getting the correct answer, then adding a second look to the first opinion is a very solid place to begin to improve the accuracy of the total diagnostic picture.

I was very surprised when I asked my surgeon what was the consensus about the error rate for pathology analyses, and she nonchalantly ventured that the generally accepted error rate was about 10%. Imagine that your life depends on the accuracy of a given diagnosis, and that in ten percent of the cases, a second-look would reveal that the facts were actually different. There is a decent body of research on the rate of disagreement amongst pathologists, like this study, by Canadian oncologist, Dr. E. Rakovitch, of Sunnybrook Hospital in Toronto. If you saw the news reports about Stronach’s DCIS and mastectomy back in June, you will have seen Dr. Rakovitch interviewed in just about every report. Dr. Rakovitch’s research shows that when you get a dedicated breast pathologist to provide a second opinion on pathology slides, a significant percentage of errors show up from the first opinion, resulting in a change of treatment plans in many of the cases (29%).

I searched out a breast pathologist, and an expert oncologist who specializes in DCIS, and together, they have agreed to provide a second opinion. I am really glad that I followed my gut feeling about the complexities of my case, and my family history. I am incredibly grateful to the doctors who helped me to find the right people to provide the second opinion. I’ll know more when I meet with the oncologist in about ten days. I am really nervous about opening up the space of uncertainty again. However, in fact, the space has always been open. All I am doing is gathering more knowledge with which to interpret the various uncertainties.

After my visit with the new team, I’ll update you. When I know, you’ll know.