Bronchioloalveolar carcinoma, or BAC, is a unique subtype of non-small cell lung cancer (NSCLC) that has unique features in terms of the demographics of who gets it, how it appears on scans, how it often behaves, and potentially in how it responds to treatment. It is a subset of lung cancer for which most of what we know emerged in the last 10 years, with our understanding of this entity, and even the definition of BAC, still evolving. What is BAC? BAC was first identified and defined as a separate subtype of lung cancer by Dr.

In one of my earliest posts about bronchioloalveolar carcinoma (BAC) (in the dark ages, pre-Twitter), I wrote on the subject of managing small BAC-type lesions, which tend to appear as small hazy areas called "ground glass opacities" (GGOs) and suggested that some of these cancers may be so indolent that they don't need to be treated, even if they have the word "carcinoma" in the diagnosis.

This is the first part of a case presentation I did with two great colleagues: Dr. Anne Tsao, who is a medical oncologist and lung cancer expert at MD Anderson Cancer Center in Houston, and Dr. Alex Farivar, who is a terrific thoracic surgeon at my own institution, Swedish Cancer Institute in Seattle.

I just wanted to tell people about a remarkable patient I just saw who is delighted to have had a remarkable response to Tarceva a few years after responding to Iressa. She made my day. In truth, her case was remarkably long before this. She was diagnosed with bronchioloalveolar carcinoma (BAC) all the way back in 1995 (I was finishing med school, no kids -- life was simpler then). She had undergone a left lower lobectomy for localized disease initially, but her cancer recurred in late 1998, confirmed on a bronchoscopy, and she began experiencing a cough then.

The most expert lung cancer pathologists in the world are planning a revision of the classification of lung adenocarcinomas that is expected to be approved and implemented next year, and it's going to make some big changes. Specifically, it's planning to eliminate the diagnosis of bronchioloalveolar carcinoma (BAC), reflecting our evolving understanding of this disease.

Here's a video slide presentation that provides a basic introduction to bronchioloalveolar carcinoma (BAC), including the demographics, natural history, imaging appearance, and patterns of response that make it a unique subpopulation within lung cancer. The audio only version is below the video.

In my last post I outlined the typical clinical scenario for pneumonic bronchioloalveolar carcinoma (BAC), which is typically the mucinous subtype of this unusual disease. In fact, we are still actively learning a great deal about BAC, enough for the lung cancer experts to begin to develop a more sophisticated view that the mucinous and non-mucinous subtypes have different behaviors and respond differently to treatments.

One of the issues with BAC is that I've referred to it as potentially very indolent, but as we've learned more about BAC, it's become clear that there is a great degree of heterogeneity in BAC cases. We're learning that the cases that are more often slowly progressing and sometimes exceptionally responsive to EGFR inhibitors like tarceva and iressa are far more likely to be non-mucinous BAC. These typically have the appearance of innumerable small nodules throughout the lungs.

Warning: this symptom can be a little gross, so the delicate flowers out there should skip this post.