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Invasive Lobular Breast Cancer May Have Worse Prognosis than Ductal Cancer

— Analysis highlights need for further research, says Megan Kruse, MD

MedpageToday

An analysis of the largest recorded cohort of patients with invasive lobular breast cancer (ILBC) demonstrates that outcomes are significantly worse when compared with invasive ductal breast cancer, highlighting a significant need for more research and clinical trials on patients with ILBC. The findings were presented at the virtual 2020 San Antonio Breast Cancer Symposium.

In this exclusive 51˶ video, , of the Cleveland Clinic, explains the multi-institutional study and the insights in provides for future prognostic research.

Following is a transcript of her remarks:

This work was spearheaded by clinicians who are interested in lobular breast cancer, and trying to figure out how lobular breast cancer is different than ductal breast cancer in a way that would be meaningful for patient care. And so since lobular breast cancer is about 10-15% of all the breast cancers we see, we knew that this work would have to be done on a multi-institution basis.

And so Cleveland Clinic, the University of Pittsburgh Medical Center, and Ohio State University got together as the Great Lakes Breast Cancer Consortium, and pulled all of our invasive lobular and invasive ductal cancer cases that had been seen from 1990 to the present. And then what we did is we looked at all of the details of these patient cases from the cancer-specific treatments as well as the tumor characteristics, lymph node size, and if there were any genetic and genomic information available for these cases.

What we ultimately found was that for lobular cancer patients, those tumors were often diagnosed at a higher stage -- meaning larger tumor size and greater lymph node involvement. These were also diagnosed in patients who were of older age compared to the ductal cancer patients, and the patients in the lobular cancer group were less likely to be HER2-positive and less likely to receive chemotherapy.

Ultimately, when you looked at the outcomes for the lobular patients compared to the ductal cancer patients, we found that the 5-year overall survival was pretty similar between the two patient groups. However, when you looked at 10-year survival, we actually found a slight decrease for the lobular cancer patients compared to the ductal cancer patients.

And this is a clinical feature that I think a lot of breast cancer oncologists will note about lobular cancer, that these patients tend to have late recurrences, sometimes years outside the window of their initial treatment, or maybe when they're even following up with us oncologists. And so certainly something worthy of additional study.

Thus far the work that was presented focused mainly on these clinical and treatment characteristics, but not necessarily in as much in a comparative way as we would like.

The hope moving forward would be to do analysis that looked at comparing outcomes based on these different aspects of treatments. For example, looking at the role of chemotherapy and looking at the role of endocrine therapy, looking at the role of radiation.

We also have a really robust database of metastatic recurrence information, including metastatic sites. And we'd like to dive into that a little bit further, knowing that clinically the metastatic patterns for invasive lobular cancer seemed to be different than those of invasive ductal cancer.

It would be wonderful to see if there are any survival differences based on these different patterns of recurrence. We're not quite sure if the numbers in this study will allow that type of analysis yet, but I think that will lead the way in answering some basic clinical questions now that this work forms the foundation that lobular cancer really does seem like a different clinical entity than invasive ductal carcinoma of the breast.

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    Greg Laub is the Senior Director of Video and currently leads the video and podcast production teams.