Mrs Y, 38, was recently diagnosed with left breast cancer and she underwent left mastectomy and axillary clearance 3 weeks ago. Histopathology reported infiltrating ductal cancer Grade 3, T3N0M0 (stage 2), ER negative, Her2 negative, LVI positive, margin clear. She was planned for adjuvant chemotherapy and radiotherapy to left chest wall.
She wanted to know why she needs to undergo adjuvant chemotherapy?
Adjuvant treatment is the additional treatment given after primary surgical treatment to increase the chance of cure.
Yes, cancer can be cured if it’s detected at earlier stage and patients complete multimodality treatments.
Fisher hypothesis, “that breast cancer was a systemic disease in that tumor cells were likely to have been disseminated throughout the body by the time of diagnosis and that more expensive locoregional therapy was unlikely to improve survival.”
No matter how good a surgeon or how radical a surgery is, breast cancer will always recur if there is no systemic treatment/ adjuvant after surgery (unless in very early stage breast cancer).
Thus, systemic treatments; adjuvant chemotherapy, hormonal and/ or targeted treatments is/ are needed to deal with breast cancer, which is a systemic disease.
For the patient above, her systemic treatment will only be adjuvant chemotherapy as she had negative estrogen receptor (ER) and Her2.
Unlike in advanced cancer where I like to see which sequence of chemotherapy or treatments will help to prolong progression free survival and overall survival, the aim adjuvant treatment here is for cure and for patients to live their natural life fully.
As the aim is for cure, there will be no subsequent chemotherapy after the first, the only and the most important one.
Which adjuvant chemotherapy regime offer the highest chance of cure?
Another way to understand the importance of adjuvant chemotherapy is to key in relevant information from her HPE report into Predict ver 2.0 and you can see the graph below to see the difference in overall survival (2nd vs. 3rd generation chemotherapy).
With 2nd generation chemotherapy:
With 3rd generation chemotherapy:
As you can see above, addition of adjuvant chemotherapy improve both 5- and 10-year survival and further improvement can be obtained by using third generation adjuvant chemotherapy.
One more thing, I just explained one very specific subset of breast cancer above, which is triple negative breast cancer (estrogen receptor, progesterone receptor and Her2 negative).
With other subsets such as estrogen receptor positive or/ and Her2 positive (overexpressed), adjuvant treatments gets even more complicated with availability of many new and effective treatments, which contributes to higher chances of cure!