I agree: A new chapter!
You stayed on the battlefield, and as a warrior-survivor completely changed the therapeutic stance of the lung oncologist who now seems to have finally done his homework and woken up to the fact the durable response and long-term survival is possible from brain metastasis, something I have been preaching - and documenting - through my CNS Review for years (I have several lung cancer consults with CNS disease who are survivors out to 6+ years, and the day is young still). CNS disease from both breast and lung cancer is highly treatable and with highly favorable responses. In addition you have minimal CNS disease with a small tumor burden (I would hazard sub-centimeter, namely millimeter, size, of slight clinical consequence), and certainly SRS (stereotactic radiosurgery) would be available to you to remit this solitary lesion, if it is not remitted by the proposed biological therapy (BT).
The Majesty of Erlotinib (Tarceva)
I am in lung cancer a strong advocate of EGFR TKIs (tyrosine kinase inhibitors), especially erlotinib (Tarceva) which I regard as our single best agent in this arena. We know from numerous recent studies (reviewed by me as of beginning of this month) that
- the EGFR TKI erlotinib (Tarceva) is active in patients with brain metastases from NSCLC,
- in NSCLC patients with CNS disease, EGFR mutation status is associated with improved survival, independent of age, functional status, extracranial disease status, and even independent of the number of brain lesions, and
- EGFR mutation predicts unique sensitivity, response, as well as survival to EGFR tyrosine kinase inhibitors (TKIs) like Tarceva.
[And this is true also of patients with leptomeningeal metastasis (Hyeon Gyu and colleagues at Seoul National University)].
Reaping the Harvest
As to the exceptional benefit of EGFR TKIs in CNS disease, let me first note that April Eichler at the Pappas Center for Neuro-Oncology (Boston) and colleagues recently conducted a large retrospective study, and of five patients with EGFR-mutant tumors and asymptomatic multiple brain metastases treated with erlotinib (Tarceva) as primary therapy, two had complete and sustained responses, and I should note one was for almost three years (32 months), and other trials show outliers even past this.
So pooling the overall response rate in these and in other prospective trials of erlotinib (Tarceva) exceed or equal at least 75% for all sites. Thus, the Spanish Lung Cancer Group followed the CNS response of seven chemotherapy-naïve patients with an EGFR mutation given erlotinib (Tarceva) at the optimal dose of 150 mg/d. They reported four patients with a complete response and three with a partial response to this EGFR inhibitor, that is, an astounding 100% response rate of brain metastases, demonstrating that in a molecularly selected population of EGFR+ patients with brain metastases, the biological agent erlotinib (Tarceva) can achieve high response rates in a metastatic site that historically has been refractory to chemotherapy agents.
In addition, Houman Fekrazad and colleagues at the University of New Mexico document the case study of a stage IV adenocarcinoma lung patient with multiple brain metastases, who after erlotinib (Tarceva) 150 mg/d, demonstrated at the 8 month follow-up a complete resolution of the brain metastases, and Chris Boshoff's team at Wolfson Institute for Biomedical Research present another such case study, with complete response of brain metastases 6 weeks after starting erlotinib.
Furthermore, Rut Porta with the Catalan Institute of Oncology, and colleagues found in a retrospective study of the Spanish Lung Adenocarcinoma Data Base that erlotinib (Tarceva) improves survival in selected patients with brain metastases from NSCLC. In patients who harbored the EGFR mutation, the objective response rate (ORRR) was an exceptional 82.4%, with 47.1% of these patients having complete resolution of all brain metastases, while 35% had partial responses. There were no responses in any patient without EGRF mutation. Median progression-free survival (PFS) in EGFR+ patients was twice that of the non-mutated EGFR controls, while median overall survival (OS) in the EGFR+ groups was four times as long as the controls.
Finally, another bonus as it were: the efficacy of erlotinib (Tarceva) in brain metastases is paralleled by its efficacy in the lung primary lesions and in other metastatic sites; that is, erlotinib (Tarceva) is a highly active, all-site biological agent, operating not just in CNS disease, but also in visceral disease (lung, liver) among other sites. Thus, all patients with EGFR mutations responding to treatment within the brain also responded in the extracranial lesions. In this sense erlotinib (Tarceva) is a pan-systemic biological agent of, I consider, breakthrough importance and clinical impact in lung cancer (and in other cancers, including breast cancer, as well, where it is now being heavily investigated.
As to the boswellic acids/AKBA, yes, they can supplement the neural activity of your biological therapy, and mitigate the development of any cerebral edema although with oligometastatic disease, I do not necessarily anticipate any such development. In addition should erlotinib (Tarceva) not wholly remit the small brain lesion, SRS is always available subsequently for just that purpose, so you have many promising options (and more beyond even these, should they be needed).
So enjoy the support and love of your sisters and husband and expanded family, one distinguished member of which is Hope.
Onward for some more chapters!
Breast Cancer Watch