Predicting the sites of metastases from lung cancer using molecular biologic markers

Association of Ki-67, p53, and bcl-2 expression of the primary non-small-cell lung cancer lesion with brain metastatic lesion

PURPOSE

The study was conducted to determine whether immunohistochemical analysis of Ki-67, p53, and bcl-2 in patients with non-small-cell lung cancer is associated with a higher rate of brain metastases and whether the intrapatient expression of these biomarkers (in the primary tumors vs. brain lesions) is similar.

METHODS AND MATERIALS

At the M. D. Anderson Cancer Center, tumors from 29 case patients with primary lung tumor and brain metastasis and 29 control patients with primary lung tumor but no brain metastasis were resected and examined for immunohistochemical expression. Ki-67, p53, and bcl-2 were analyzed in resected primary lung, lymph node, and metastatic brain tumors. Each control patient was matched by age, gender, and histology to a patient with brain metastasis.

RESULTS

No significant differences in patient survival characteristics were detected between the case group and control group. Also, difference in patient outcome between the two groups was not generally predicted by biomarker analysis. However, when the groups were combined, the biomarker analysis was predictive for certain patient outcome end points. Using median values as cutoff points between low and high expression of biomarkers, it was observed that high expression of Ki-67 (>40%) in lung primaries was associated with poorer disease-free survival (p = 0.04), whereas low expression of p53 in lung primaries was associated with poorer overall survival (p = 0.04), and these patients had a higher rate of nonbrain distant metastases (p = 0.02). The patients with brain metastases were particularly prone to developing nonbrain distant metastases if the percentage of p53-positive cells in brain metastases was low (p = 0.01). There was a positive correlation in the expression of Ki-67 (p = 0.02)(r(2) = 0.1608), as well as p53 (p < 0.001) (r(2) = 0.7380), between lung primaries and brain metastases. Compared to Ki-67 and p53, bcl-2 was the least predictive.

CONCLUSION

Differences in biomarker expression between the case and control groups did not serve as significant predictors of brain metastasis or patient survival. There was a strong correlation between lung primary biomarker expression and brain metastasis expression for Ki-67 and p53. Univariate analysis showed that low p53 and high Ki-67 expression predicted poor prognosis. This study shows that there may be a strong correlation between biomarker expression in non-small-cell lung cancer primary tumors and their brain metastases.

Brain metastases in locally advanced nonsmall cell lung carcinoma after multimodality treatment: risk factors analysis

BACKGROUND

Brain metastases (BM) are frequent sites of initial failure in patients with locally advanced nonsmall cell lung cancer (LAD-NSCLC) undergoing multimodality treatments (MMT). New treatment and follow-up strategies are needed to reduce the risk of BM and to diagnose them early enough for effective treatment.

METHODS

The incidence rate of BM as the first site of recurrence in 112 patients with LAD-NSCLC treated with the same MMT protocol was calculated. The influence of patient, disease, and treatment-related factors on the incidence of BM and on the time-to-brain recurrence (TBR) was analyzed.

RESULTS

BM as the first site of failure was observed in 25 cases (22% of the study population and 29% of all recurrences). In 18 of those cases, the brain was the exclusive site of recurrence. Median TBR was 9 months. The 2-year actuarial incidence of BM was 29%. Central nervous system (CNS) recurrence was more common in patients younger than 60 years (P = 0.006) and in whom bulky (> or = 2 cm) mediastinal lymph nodes were present (P = 0.02). TBR was influenced by age (P = 0.004) and by bulky lymph node disease (P = 0.003). Multivariate analysis confirmed the prognostic role of age, whereas the presence of clinical bulky mediastinal lymph nodes was of borderline significance.

CONCLUSIONS

Our study confirmed a high rate of BM in patients with LAD-NSCLC submitted to MMT. Most of these CNS recurrences were isolated and occurred within 2 years of initial diagnosis. Age younger than 60 years was associated with an increased risk of BM and reduced TBR, whereas the presence of clinical bulky mediastinal lymph nodes was of borderline significance. Although our data require further validation in future studies, our results suggest that additional trials on prophylactic cranial irradiation and on intensive radiologic follow-up should focus on these high-risk populations.

Management of advanced non-small cell lung cancer: current trends

Carcinoma of the lung continues to be the leading cause of cancer-related deaths for Americans. Major efforts have been made in the treatment of advanced non-small cell lung cancer; chemotherapy and investigations in the last decade have yielded a number of new agents and combinations. Despite progress with newer agents for the treatment of non-small cell lung cancer, only 14% of patients with the disease are alive 5 years after the initial diagnosis. Toward improving the outcome of patients with advanced non-small cell lung cancer, a few trends can be identified. These include further work on combination chemotherapy, the introduction of novel biologic agents into treatment, and predicting which patients will respond to chemotherapy. These trends are discussed in this review.

Molecular staging of lung and esophageal cancer

In both esophageal and NSCLC, the TNM stage at diagnosis remains the most important determinant of survival. Significant research to investigate the biology of NSCLC and esophageal carcinoma is ongoing, and the roles of proto-oncogenes, tumor suppressor genes, angiogenic factors, extracellular matrix proteases, and adhesion molecules are being elucidated. While evidence is accumulating that various markers are involved in NSCLC and esophageal tumor virulence, the current studies are compromised by small sample sizes, heterogeneous populations, and variations in techniques. Large prospective studies with homogenous groups designed to evaluate the role of these various markers should clarify their potential involvement in NSCLC and esophageal cancer. Identification of occult micrometastases in lymph nodes and bone marrow using immunohistochemical techniques and rt-PCR is intriguing. These techniques are promising as a method to more accurately stage patients, and therefore to predict outcomes and to determine therapies. Perhaps the most promising area of research is the development of novel drugs whose mechanism of action targets the pathways of various molecular markers. Molecular biologic substaging offers an opportunity to individualize a chemotherapeutic regimen based on the molecular profile of the tumor, thus providing the potential for improved outcomes with less morbidity in patients with both NSCLC and esophageal cancer.