Risk of recurrence of resected stage I non-small cell lung cancer in elderly patients as compared with younger patients.

PURPOSE: Half of all patients with non-small cell lung cancer (NSCLC) are 70 years or older at the time of diagnosis. Surgery is an option for fit elderly patients with early stage disease, but rates of disease recurrence after surgical resection are not well described. We report the outcomes in elderly patients (70 years or older) with stage I NSCLC after surgical resection. PATIENTS AND METHODS: We conducted a retrospective study of patients diagnosed with stage I NSCLC after surgical resection at Washington University School of Medicine-Alvin J. Siteman Cancer Center from 1990 to 2000. Demographic, pathologic, treatment, and follow-up data were collected. Recurrence rates and overall survival were calculated by the Kaplan-Meier method. Multivariate Cox proportional hazards models were used to detect associations between potential prognostic factors and survival and recurrence. RESULTS: Of the 715 patients with stage I NSCLC, 286 were 70 years or older at diagnosis. In this elderly cohort, the median age was 74 years (range, 70-89 years) and 140 of them were women (49%). Lobectomy was performed in 237 patients (83%) whereas 43 patients (15%) had a wedge or segmental resection, and six patients (2%) underwent pneumonectomy. Clinical and pathologic characteristics were not statistically different between the elderly and younger cohorts, with the exception that older patients were more likely to be white (90% versus 80%, p = 0.0003) and less likely to be smokers (88% versus 95%, p = 0.019) compared with the younger cohort. With a median follow-up of 4.6 years, the overall 5-year survival rate was 52% with a 5-year recurrence rate of 24%. In comparison, the patients younger than 70 years had a 5-year survival rate of 67% (p < 0.001) and a 5-year recurrence rate of 24%. CONCLUSIONS: Although overall survival was worse in elderly patients, estimated disease recurrence rates after resection were identical.

A clinical model to estimate recurrence risk in resected stage I non-small cell lung cancer.

OBJECTIVE: There are no reliable markers to predict recurrence in resected Stage I non-small cell lung cancer (NSCLC). A validated clinical model to estimate the risk of recurrence would help select patients for adjuvant therapy. METHODS: We reviewed the medical records of 715 patients who had a potentially curative resection for Stage I NSCLC at our institution from 1990 to 2000. Recurrence rates were estimated by the Kaplan-Meier method. A model to estimate risk of recurrence was developed by combining independent risk factors. RESULTS: With a median follow-up of 4.7 years, the 5-year survival rates for Stages IA and IB were 66% and 55% respectively, and 5-year recurrence rates were 19% and 30%, respectively. Four factors were independently associated with tumor recurrence: tumor size >3 cm (hazard ratio [HR] = 2.4), surgery other than lobectomy (HR = 2.0), nonsquamous histology (HR = 1.4), and high-grade cellular differentiation (HR = 1.4). A scoring system for recurrence was developed by assigning 2 points for each major risk factor (tumor size and surgery) and 1 point for each minor risk factor (histologic subtype and cellular grade). Scores were grouped as low (0-1), intermediate (2-3), and high (>3), yielding 5-year estimates of risk of recurrence of 14%, 27%, and 43%, respectively. CONCLUSION: This model, based upon readily available clinicopathologic characteristics, can estimate the risk of recurrence in Stage I NSCLC, independent of T classification. This model could be used to select patients for adjuvant therapy if validated in independent data sets.

EGFR-T790M is a rare lung cancer susceptibility allele with enhanced kinase activity.

The use of tyrosine kinase inhibitors (TKI) has yielded great success in treatment of lung adenocarcinomas. However, patients who develop resistance to TKI treatment often acquire a somatic resistance mutation (T790M) located in the catalytic cleft of the epidermal growth factor receptor (EGFR) enzyme. Recently, a report describing EGFR-T790M as a germ-line mutation suggested that this mutation may be associated with inherited susceptibility to lung cancer. Contrary to previous reports, our analysis indicates that the T790M mutation confers increased Y992 and Y1068 phosphorylation levels. In a human bronchial epithelial cell line, overexpression of EGFR-T790M displayed a growth advantage over wild-type (WT) EGFR. We also screened 237 lung cancer family probands, in addition to 45 bronchoalveolar tumors, and found that none of them contained the EGFR-T790M mutation. Our observations show that EGFR-T790M provides a proliferative advantage with respect to WT EGFR and suggest that the enhanced kinase activity of this mutant is the basis for rare cases of inherited susceptibility to lung cancer.

Identification of a novel tumor suppressor gene p34 on human chromosome 6q25.1.

In this study, we observed loss of heterozygosity (LOH) in human chromosomal fragment 6q25.1 in sporadic lung cancer patients. LOH was observed in 65% of the 26 lung tumors examined and was narrowed down to a 2.2-Mb region. Single-nucleotide polymorphism (SNP) analysis of genes located within this region identified a candidate gene, termed p34. This gene, also designated as ZC3H12D, C6orf95, FLJ46041, or dJ281H8.1, carries an A/G nonsynonymous SNP at codon 106, which alters the amino acid from lysine to arginine. Nearly 73% of heterozygous lung cancer tissues with LOH and the A/G SNP also exhibited loss of the A allele. In vitro clonogenic and in vivo nude mouse studies showed that overexpression of the A allele exerts tumor suppressor function compared with the G allele. p34 is located within a recently mapped human lung cancer susceptibility locus, and association of the p34 A/G SNP was tested among these families. No significant association between the less frequent G allele and lung cancer susceptibility was found. Our results suggest that p34 may be a novel tumor suppressor gene involved in sporadic lung cancer but it seems not to be the candidate familial lung cancer susceptibility gene linked to chromosomal region 6q23-25.

A phase II study of irinotecan and carboplatin in advanced non-small cell lung cancer with pharmacogenomic analysis: final report.

PURPOSE: We conducted a phase II study of carboplatin and irinotecan in patients with advanced non-small cell lung cancer (NSCLC). In addition, we studied the correlation between certain genotypes of enzymes involved in irinotecan metabolism with efficacy and toxicity. PATIENTS AND METHODS: Patients with stage IIIB, IV, or recurrent NSCLC received a combination of irinotecan and carboplatin every 3 weeks at a dose of 200 mg/m2 and area under the curve of 5. Pharmacogenomic analysis was performed on several genes of interest (ABCB1, CYP3A4*1B, ERCC2, GSTP1, UGT1A1*28, and XRCC1). RESULTS: Forty-two patients enrolled between December 2001 and January 2004. Six patients achieved partial responses (14%), and 19 (45%) had stable disease. The median progression-free survival was 6.9 months. The median overall survival was 11.7 months, with 1-year overall survival of 42%. The most common toxicities were hematologic; grade 3 or 4 neutropenia was experienced by 26 patients (62%) during treatment, and 15 patients (36%) experienced grade 3 or 4 thrombocytopenia. The homozygous UGT1A1*28 (7/7) genotype was associated with grade 4 neutropenia in three of four patients (75%), but only eight out of 30 (27%) with 6/6 or 6/7 genotypes experienced grade 4 neutropenia (p = 0.09). None of the 14 patients with the GSTP1 I105V A/A genotype had a partial response, as opposed to five out of 19 (26%) of those with the G/A or G/G genotypes (p = 0.057). CONCLUSION: The combination of carboplatin and irinotecan is an active combination in NSCLC, with response rates comparable with other platinum-containing doublets. Further studies with irinotecan should incorporate prospective pharmacogenomic analysis to identify markers for response and toxicity.