Bronchioloalveolar Carcinoma in African Americans: DISCUSSION

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In our study, all patients were African Americans, therefore we had the opportunity to review the clinical and pathophysiological features of ВАС exclusively in this ethnic group. ВАС was the least common lung tumor in our series and accounted for only 3% of cases. This is in accordance with the literature reporting the incidence of ВАС at 1-9%. Women accounted for one-third of our patient population similar to the 40% of previously reported ВАС. ВАС is a unique patho­logical entity that is distinct from pulmonary adenocarcinoma. Although histological feaures may overlap, ВАС demonstrates a growth pattern along preexisting lung architecture without invasive or destructive growth. The association of ВАС with scarring has been recognized for years.

Two of our patients had previous pulmonary tuberculosis and ВАС developed in those scars. Radiologically, ВАС was seen in several patterns. Lung mass was the most common form of presentation (68%), and the upper lobes were most commonly involved. In contrast to previous studies, the finding of a solitary nodule was uncommon (16%), and all of these cases were discovered incidentally on chest x-rays obtained for other reasons. Some patients presented as unresolving pneumonia. Consolidation, cavitation, collapse, atelectasis, and pleural effusions were also noted. tadacip

Our data also confirm that the natural history of ВАС, as reported in previous studies, is different from other types of bronchogenic carcinoma in that survival is in general prolonged and mostly influenced by stage rather than by lymph node metastases. ВАС usually tends to be localized (75%), but, in our study, 47% of patients had stage-1 disease. Lymph node metastases were present in 26% of the patients. The lymph node involvement did not affect the overall survival of our patients, confirming the previous reports. Five-year survival of patients with stage-1 disease treated by surgery was 75%. This is better than with other types of lung cancers. Long-term survival is influenced by the histopathological type of ВАС. Mucinous ВАС is associated with the worst prognosis. In our study patients, those with mucinous ВАС had the worst prognosis. The nonmucinous forms had better survival, most having localized disease. Both of our patients with scarring from previous tuberculosis had favorable outcomes. Bronchorrhea reported as hallmark for mucinous ВАС was not seen in any of our patients. Although rare, it can cause electrolyte abnormalities and intrapulmonary shunting resulting in severe hypoxemia. The eight patients in our study who underwent resection had the best five-year survival (75%).

CONCLUSION

ВАС has a unique natural history that is influenced more by local neoplastic process than by lymph node metastases. Early pulmonary resection is safe and can be curative. Even if multiple unilateral foci are present, surgery should be strongly considered. Our study is the first published review of clinical and pathophysiological features of ВАС in African Americans. The study showed differences in the incidence among smoking status and symptoms (productive vs. non productive), histopathology, and radiological features. ВАС can present with a wide variety of clinical/radiological features, resulting in missed or delayed diagnosis. Patients with localized disease have good prognosis if detected early. The diffuse metastatic/ pneumonic form is an aggressive disease with a poor prognosis. As the incidence of the ВАС is rising— especially in females and nonsmokers—primary care physicians must be vigilant and familiar with the varied manifestations of this disease in order to allow for timely diagnosis and treatment of potentially curable early-stage disease. Novel approaches, such as continuous four-day Paclitaxel infiision and targeted systemic therapy, should be considered when appropriate in the management of ВАС. buy antibiotics canada