Early-stage breast cancer, HER2-positive, Subcentimeter tumors, T1aN0M0, Very small tumors

Retrospective Studies

You’ll make yourself nuts if you read studies back to back that seem to contradict each other. One study will say there’s a low risk of recurrence, yet the next one will say the risk is high. I have found it’s easier if I take breaks from this stuff.

My friend A.C.S. summarized cancer treatment decisions like this: it’s like gambling – only you’re making life or death decisions based on statistics.

As I mentioned on the “Start here” page, there aren’t any current medical studies featuring women who take no drugs with a T1a or T1b HER2-positive diagnosis. But there are many retrospective studies to consider. Just note that T1a is usually not the focus of the study, and if it is, it’s a relatively low number of patients.

Good luck.

Distant recurrence risk for T1a and T1b HER2-positive patients: https://bit.ly/2MqE1Dw (this is highly cited as the “Kaiser study”) – or here: https://www.researchgate.net/profile/Louis_Fehrenbacher/publication/262815371_Distant_Invasive_Breast_Cancer_Recurrence_Risk_in_Human_Epidermal_Growth_Factor_Receptor_2-Positive_T1a_and_T1b_Node-Negative_Localized_Breast_Cancer_Diagnosed_From_2000_to_2006_A_Cohort_From_an_Integ/links/5669984f08ae62b05f025037/Distant-Invasive-Breast-Cancer-Recurrence-Risk-in-Human-Epidermal-Growth-Factor-Receptor-2-Positive-T1a-and-T1b-Node-Negative-Localized-Breast-Cancer-Diagnosed-From-2000-to-2006-A-Cohort-From-an-Integ.pdf

Eight percent chance of recurrence for triple positive T1a and T1b cancer patients, according to this retrospective study: https://www.nature.com/articles/6604940 (***This study breaks down T1a from T1b, as well as hormone positive and negative groups, Ki67 scores, neoadjuvant treatment, and more, which was rare to find.)

High risk of recurrence is a highly cited project by researchers at M.D. Anderson in Texas: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2792998/ (This study confirmed the importance of biomarkers in small tumors.)

  • Note, this study and a similar Italian one prompted an editorial in the Journal of Clinical Oncology, which stated: “…We suggest that consideration of trastuzumab plus chemotherapy generally be limited to patients with T1b or larger cancers, and we believe that among patients with small T1a or microinvasive cancers, it is less likely that the trade-offs of risk and benefit warrant chemotherapy plus trastuzumab…” Read the full editorial here: http://ascopubs.org/doi/full/10.1200/JCO.2009.24.2222

Overview of many retrospectives studies: https://www.croh-online.com/article/S1040-8428(17)30505-X/pdf (follow footnote links to read individual studies that are referenced)

Effects of chemotherapy on very small tumors, in a multi-institutional retrospective study: https://www.ncbi.nlm.nih.gov/pubmed/23354365

Prognosis of patients with T1a,bN0M0http://ascopubs.org/doi/full/10.1200/jco.2005.02.8035?utm_medium=cpc&utm_campaign=J_Clin_Oncol_TrendMD_0&utm_source=TrendMD

A large, French retrospective study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4433506/

This is an excellent overview of size and hormones and how it relates to the recommendations oncologists make for patients: https://ecancer.org/journal/9/full/593-infracentimetric-her-2-positive-breast-tumours-review-of-the-literature.php

A huge study on very small invasive and non-invasive cancer analyzed more than half a million breast cancer cases going back to 1990: https://link.springer.com/article/10.1007%2Fs10549-017-4572-2

  • Note, that study is behind a paywall, but you can read the abstract. You might be able to get more information if you politely contact the lead author.

A 2014 study on tumor size and hormones (and HER2 status) found the “absolute benefit” for chemotherapy and trastuzumab for most T1a patients to be small, but recognized some patients might greatly benefit.

This study examined HER2-positive, and HER2-negative, so be careful when you are reading through it that you don’t confuse things. Figure 2 is quite interesting, and the second row is HER2-positive. The study can be found here: http://ascopubs.org/doi/full/10.1200/JCO.2013.53.1608



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.













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