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bac features


carlton

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Hi Carlton

BAC stands for bronchoalveolar cancer, which is a subgroup of NSCLC. I do not know much about it, other than it tends to be more confined to the lungs, and I understand it may respond better to Iressa. I'm sure other members will be able to help you with more info. You could also do a web search - there is alot of info out there!

Karen

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Hi, Carlton,

Bronchioloalveolar Carcinoma (AKA BAC) is an unusual form of Lung Cancer. It's considered to be a subgroup of Adenocarcinoma, but many lung cancer experts want it to be classified separately from Adeno cancers.

BAC is further divided into groups based on it's characteristics. There's mucinous, non-mucinous, single nodule, multifocal, solid tumor, semisolid tumor and nonsolid tumor. It typically stays within the confines of the lung, but can spread to distant sites, and like a breast or colon cancer it can spread just about anywhere when it does escape the confines of the chest.

When someone is diagnosed with Adenocarcinoma with BAC features it means that the tumor(s) have characteristics of both plain adenocarcinoma as well as characteristics of BAC. And what that really means in real world terms is that our type of cancer may or may not progress and respond to conventional cancer treatments in ways that other forms of Lung Cancer respond. A BAC component to cancer is a complicating factor.

You can actually learn a lot about BAC and ADC with BAC features if you search under Veterenary Medicine (BAC affects cats and sheep). Also, search under Lung Cancer and Ioninzing radiation exposure.

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Hi Fay,

Didn't know that BAC affected cats. My kitty just died Sunday from either a blood clot or LC. He had a cough for about 1-1/2 months and I had him on antibiotics for about a week. Seemed to be getting better, cough almost gone. Came home from church Sunday and he was in duress. Couldn't breathe and had a gurgling sound in his throat. We rushed him to emergency vet and he passed 10 minutes before we got there. My vet said it was either the clot ot LC. It happened so fast, totally unexpected... :cry:

Hope all is well for you... Blessings and prayers for you.

Karen

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Carlton,

I was told that BAC tends to be a little more slower growing then regular adenocarcinoma - so the prognosis might be slightly better. Also, BAC tends to show up on both sides of the lungs early on, and sometimes if it is caught early enough, they can do surgery on both sides of the lung. We had a second opinion at UC Davis Medical Center and the MD said if you do have BAC, it tends to respond better to IRESSA instead of conventional chemotherapy. The only way to know definatively if a person has BAC is to get a tissue sample, along with the surrounding tissue. BAC tends to have a fluffy, pneumonia like appearance on the xrays and to be more confined to the outer areas of the lungs instead of the main bronchial areas. They are treating my dad as if he has BAC and since my dad didn't really want to take chemo, we thought it wouldn't hurt to try IRESSA. Our oncologist said he had a pt with BAC who has survived 4-5 years, but she also took chemo. Anyways, hope that helps. shirley

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Treatment Options for Bronchioloalveolar Carcinoma?

Question

A 55-year-old female former smoker presents with cough and shortness of breath. She was diagnosed with bronchioloalveolar cell carcinoma (BAC), possibly involving both lungs. No other metastases were noted on CT scan of the chest and abdomen, PET scan, or MRI of the brain. Her performance status is 1 and she desires aggressive treatment. What would you suggest?

Response from Vincent Miller, MD

Assistant Attending Physician, Memorial Sloan-Kettering Cancer Center, Thoracic Oncology Service, New York, NY

BAC is defined by the World Health Organization as a pure adenocarcinoma without evidence of vascular, pleural, or soft tissue invasion. The tumor type in its pure form is relatively rare, but its incidence is increasing.[1] Moreover, recent work suggests that some adenocarcinomas, either those containing foci of BAC (adenocarcinoma with BAC features) or those that are predominantly BAC but have small areas of invasive adenocarcinoma (BAC with invasion), have clinical courses similar to that of pure BAC.[2] When these cases are included, a BAC component may be present in as many as 20% of non-small cell lung cancers (NSCLC).

The case described here is not unusual for BAC, which is a disease characterized by multifocal synchronous or metachronous primary tumors. Although BAC is associated with smoking, about 30% of such patients were never smokers, making for a weaker association than with other forms of lung cancer. Thus, for a given tumor burden, pulmonary function may be better in many BAC patients.

The key question is: How many foci of disease or suspected disease are present in the lungs and what is the radiographic appearance of the foci? If only 2 lesions were seen, we would pursue a biopsy of both. A differing histology or morphology would argue in favor of a surgical approach, staging each tumor independently. If a surgical approach were to be considered for similar-appearing lesions, mediastinoscopy and a quantitative ventilation/perfusion scan should first be performed. However, if N2 or N3 nodes were demonstrated, a nonsurgical approach should be considered.

By contrast, if a pneumonic form of BAC were suspected, we would be disinclined to pursue surgery because of the higher propensity for rapid dissemination of this radiographic variant within the lung and because of the poorer outcome of patients with these tumors.

Finally, if innumerable nodules or foci of disease were noted in the lungs, systemic chemotherapy should be considered. In some patients in whom radiographic stability has been documented over many months, continued expectant observation is not unreasonable, as some investigators believe BAC to be less sensitive to chemotherapy and to have a longer natural history when it is metastatic or multifocal within the lung. This observation was supported by only small, single-institutional studies. Recently, however, the Southwest Oncology Group (SWOG) described their experience with a 96-hour infusion of paclitaxel in 53 patients with BAC. A 14% response rate was noted, but median survival was approximately 1 year. Thus, this first prospective study seems to support this widely held view as well.[3]

As initial therapy, a "standard" cytotoxic doublet containing cisplatin or carboplatin is appropriate. These patients should be evaluated, and treatment decisions should be similar to those seen with other forms of NSCLC. Investigational approaches of particular interest include the use of gefitinib or erlotinib. These agents are small-molecule inhibitors of the epidermal growth factor receptor tyrosine kinase (EGFR-TKIs). Larger multicenter phase 2 trials of both drugs are ongoing or have been completed. Miller and colleagues[4] have reported a response rate of 26% with erlotinib in 50 evaluable BAC patients; West and colleagues[5] reported results of a SWOG multicenter phase 2 trial of gefitinib and noted a response rate of approximately 15%. These agents are generally well tolerated, and if response duration and survival are encouraging, they may be suitable for phase 3 study vs a cytotoxic chemotherapy regimen.

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I read this on MedScape a few days ago. One of the things that I find most interesting about BAC is the fact that when I first began to do research in earnest on the subject of BAC and ADC with BAC features (almost 5 years ago) the written opinions of the Cancer and Molecular Biology experts on the subject was that BAC and ADC with BAC features was NOT considered a smoking related cancer. They maintained that position until just about the time that so many NON SMOKING or former Light Smoking individuals who had been diagnosed with this form of Lung Cancer began to speak up and ask questions about how WE came to have Lung Cancer. Slowly....over the past few years....when reading reports on the subject of BAC I have occasionally found the words "...BAC is smoking related...", inserted here and there in various reports, but very little in the way of verifiable research cited to support that phrase.

I've lived long enough to know that if erroneous information is repeated often enough-without being called into question-it will eventually be accepted as a maxim. That is happening now on the issue of Bronchioloalveolar Carcinoma and smoking.

Our society has so much invested in the smoking-lung cancer conundrum (think all that tobacco settlement money...think all the tax income from the sale of tobacco and related products) that I now doubt that in MY lifetime we will see societal recognition of lung cancer in nonsmokers. I don't think it will be an issue dealt with appropriately until the incidence rate increases to the point that it absolutely CAN'T be ignored or glossed over. Unfortunately I see that happening if current incidence rates continue to increase as they have been over the past 5 years. Or, it may happen if we can build up some momentum and push the issue in ways that cannot be ignored.

I know that there are researchers who are looking at BAC in all it's forms, with the hopes that they can unravel the mystery of how non smokers develop lung cancer. (this extends to animal studies...BAC affects sheep, and this is an issue in areas where people's economic health is dependent upon sheep as a food source. BAC is found in cats, too.) I question the validity of the author's 30 percent never smokers figure in BAC. I want to know how many people participated in the study(ies), their diagnosis, their histories, etc. before I will accept a statement like that without supporting documentation. Especially when most of what I've read (peer reviewed literature) does not support that figure.

Okay....I'm all through with this. I disagree with just about everything this guy has to say....including his recommendations for the 55 year old patient. I sure hope she decides to do some research on her own and finds her way to this site.... :wink:

Fay A. (the Argumentative!) :)

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Fay,

Although I was a smoker for 30 years and now did not beat the gene pool!

It still amazes me how many non-smokers ther are out there with

lung cancer. I firmly believe that stress plays a big part in what happens

as it compromises one's immunity and continous stress just keeps your system down.

Just food for thought

Good luck

Hang tough

Jean

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Hi All,

I'm a former smoker and do sympathize with Fay's plight. Every time I announce I have lung cancer, there is someone (including MDs) who ask if I smoked. How irritating that must be to a never-smoker! Anyway, I believe the irony is that some day we will discover that all those fumes spewed out by cars may have a strong impact on LC formation.

Just my 2 cents,

Mark

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