New research suggests biomarkers and tumor features of breast cancer are important in deciding follow up treatment for very small HER2-positive tumors.
There is so much varied information on this. Honestly, I’d suggest going to scholar.google.com and typing in keywords specific to your case. Just make sure to include “T1a” or “T1b” and “HER2-positive”.
Tumor features and biomarkers, or basic tumor biology, including Ki-67, hormones, grade, etc.: https://www.breastcancer.org/symptoms/diagnosis/path_checklist (this is actually a downloadable booklet from breastcancer.org that explains what you’ll see on a pathology report – it’s really easy to understand)
HER2 basic background and trastuzumab development: https://www.cancer.gov/research/progress/discovery/HER2
*Nearly a quarter of women with small breast cancers at risk for distant metastases: https://www.healio.com/hematology-oncology/breast-cancer/news/online/%7Bb8ebd7ca-494e-4e43-a3ad-8f18574e9091%7D/nearly-a-quarter-of-women-with-small-breast-cancers-at-risk-for-distant-metastases (*only a small percentage in this study had HER2-positive status, and its goal is to determine the role of MammaPrint from HER2-negative guidance. More here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5846188/)
Turkish study on Ki67 threshold point: https://www.hindawi.com/journals/jo/2018/1912438/ (There is no universal consensus on the proliferation rate, or how fast the cancer cells are dividing/replicating. This study suggests researchers use the 14% mark.)
Japanese study on Ki67 index that urges pathologists and oncologists to pay more attention to this biomarker for future cancer treatment, especially for HER2-positive, luminbal b subtypes: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0119565http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0119565
This study says if the Ki67 rate is higher than 15 percent, there is a higher rate of recurrence for HER2-positive breast cancers: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5250608/
This study says a low Ki67 rate in tumors under 1 centimeter generally have a low recurrence rate, but that chance increases in HER2-positive breast cancers: https://meetinglibrary.asco.org/record/97436/abstract
This study says high-grade DCIS with comedonecrosis may lead to microinvasion more often: http://naosite.lb.nagasaki-u.ac.jp/dspace/handle/10069/38231
The information contained in this blog is not intended to be used for medical diagnosis or treatment. It should not be used in place of the advice of your doctor or other qualified health care provider.