I'm completing a chapter in a key lung cancer textbook on managing multi-focal bronchioloalveolar carcinoma, a clinical entity that is in the process of being re-labeled lepidic predominant adenocarcinoma (LPA) (lepidic meaning scale-like, which is the classic way that the cells are defined as spreading when looked at under a microscope). I suspect that it will continue to be called multifocal or advanced BAC for a long time (after all, the formal staging of small cell lung cancer goes from stages 1 to 4, but nobody ever uses that, classifying it as just limited or extensive stage).
When asked to write this chapter, I faced the challenge of there being very little actual hard data on managing multifocal BAC. Though many experts have a very similar approach, this is actually based on expertise, good judgment, and clinical experience more than data we can point to, and I don't think this approach has ever been articulated in a scientific paper or book chapter, so I'm hoping this will be a valuable addition to the literature.
As I reviewed the papers out there, what struck me most are two things:
1) There is incredible variability in the appearance and clinical behavior of what is called advanced BAC in the clinical world -- some of it is aggressive and imminently threatening, and much of it is very slow growing and among the least threatening cases ever labeled as lung cancer.
2) People with a very slow growth rate are likely to do very, very well no matter what treatments they get, as much despite as because of those treatments. In many cases, interventions are pursued on patients who are destined to do very well, and then when their short term survival is good, the people who did that intervention write a paper saying how their approach is feasible and attractive because the patients did well -- not recognizing, or at least glossing over the idea, that they were going to do very well anyway.
I would say that in no other area of lung cancer care is it more important to distinguish between what can be done and what should be done. And the real experts know when to not intervene.
So here is the algorithm I developed, which isn't beautiful, but you can see that it focuses on seeing what is actually changing rather than treating reflexively based on a label on a pathology report or single a scan finding. Essentially, it says to try to avoid intervening at all unless or until you see clinically significant change (which I would consider as something that is readily apparent as progression on scans done 6 months apart or less), and then if you see progression, clarify whether it's limited to one lesion or progressing more diffusely in multiple areas.
Also, if patients need systemic therapy, you use the same approach that you would for another non-squamous NSCLC. BAC today should be tested for the key molecular markers that can change management, most particularly EGFR mutation and ALK rearrangement, with the decision of chemo or targeted therapy as first line treatment really dictated by the molecular profile, just the way we'd approach an invasive lung adenocarcinoma.
Finally, I'll say that this concept isn't or shouldn't be unique to multifocal BAC. There are other slow-growing cancers, and if I see someone with a slow growing mesothelioma or invasive lung cancer or bladder cancer or prostate cancer, the question of whether there is clinically significant progression should come up. Though there are many people who absolutely need all of the aggressive anti-cancer treatment they can get, we treat lots of people with more therapy than is there best interests: part of that is a cultural bias among patients and doctors that we must go in, guns blazing, to meet our enemy full force. Part is that the incentives, in the US health care system at least, is to give the most care that is defensible and will be paid for.
I don't know if most people in this situation can accept remaining untreated for months or years at a time, even knowing that they have an indolent cancer. But I would advise people to think about some of these slower-growing cancers like diabetes, high cholesterol, or obesity. They represent a chronic risk to survival over years and often decades, but most people don't lose sleep over obesity or their cholesterol levels and don't rush into a triple bypass done 10 years before it might be needed just because a paper might show that people who undergo a prophylactic cardiac bypass 10 years before they would have had a clinical issue are still doing well 3 years after the surgery.
What do you think? Could you accept surveillance scans and no treatment if you were told that you have what is technically an advanced cancer, but one that is likely slow-growing and for which early intervention offers no clear benefit over later intervention? Do you believe that the treatment might be worse than the disease?