The clinical syndrome of BAC is characterized by spread primarily through the lungs, a higher proportion of never-smokers or light former smokers, a greater proportion of women, and often progresses more slowly than most other lung cancers. This clinical and radiographic (scans) scenario isn’t necessarily seen only with “pure BAC” under the microscrope from a biopsy, but rather can be a spectrum from pure BAC to part non-invasive BAC pattern and part invasive adenocarcinoma, and on the other end of the continuum is invasive adenocarcinoma, as shown in the illustration of how these appear under a microscope.
Pure BAC
Adeno w/BAC Features
Invasive Adeno
It doesn’t have to be “pure BAC” to behave like a BAC clinical picture. The variability in how BAC behaves is still poorly understood. Overall, invasive adenocarcinoma (without BAC) has a worse prognosis than adeno/BAC mix, but there’s tons we don’t know yet. Importantly, many of the amazing responders with what is called BAC actually have adenocarcinoma with BAC characteristics under the microscope. And the response rate on BAC trials of drugs like Iressa (gefitinib) and Tarceva (erlotinib) actually suggest that patients with adenocarcinoma with BAC characteristics may do better than pure BAC. One of the other complications is that there are two different types of pure BAC, mucinous and nonmucinous. In the BAC trial with Iressa, which I led and published recently, patients with mucinous pure BAC did very poorly, while those with the non-mucinous type did considerably better. In any event, most current trials for “patients with BAC” allow patients with pure BAC or adeno with BAC to participate, and then the trial tries to collect tissue from the tumors to figure out patterns of which patients are getting a benefit and which are not. Right now, we really don’t know nearly enough about the different subtypes of BAC and how they will do with various treatments. But we’re getting better all the time.
posted by Dr. West @ 11:29 am link to this post
Loading ...
November 13th, 2006 at 8:20 pm
How does one know if his BAC is mucinous or non-mucinous? This was never mentioned to me and I rarely see it defined anywhere although I have searched.
November 14th, 2006 at 6:25 am
It is can be usually found on a biopsy report such as Bronchoscope. Also it is a ask questiion for your onocolgist.
Lodis
November 15th, 2006 at 6:41 am
What impact does smoking a pipe have on the prognosis and quality of life of a person with BAC? My father has been told (or he has interpreted) that quitting smoking may not make a difference.
November 15th, 2006 at 5:59 pm
On the question of BAC subtype, it is common to have information about mucinous vs. non-mucinous NOT included on a pathology report. If there is enough tissue (which may not be the cas, depending on what kind of biopsy was done), it may help to have tissue reviewed by a pathologist with an interest/expertise in lung cancer, often at larger cancer centers.
With regard to the question on pipe smoking, this has definitely not been studied and likely will not have a major impact on the cancer either way, but his lung function from unaffected areas would be improved if he were to stop smoking. And with BAC you are often dealing with very limited lung capacity, so it helps to maximize what isn’t affected by BAC.