Lymph node metastasis and prognosis in small peripheral non-small-cell lung cancers

Clinically predictive factors of pathologic upstaging in patients with peripherally located clinical stage IA non-small cell lung cancer

OBJECTIVE

Post-surgical pathologic examination often reveals a more advanced state than clinically defined in non-small cell lung cancer (NSCLC), posing the need for careful consideration of a lesser resection. We investigated the predictive factors for the pathologic upstaging in clinical stage IA NSCLC.

METHODS

The clinical features of 253 consecutive patients with peripherally located T1N0M0 NSCLC who underwent complete resection between 1991 and 2004 were investigated in relation to pathologic T- and N-factors.

RESULTS

Of the 253 patients, 46 (18.2%) were upstaged after surgery, due to T-factor in 12 patients, N-factor in 32, M-factor in 2 and both T- and N-factors in 1. Among the clinical parameters, a higher level of serum CEA (p=0.0378) and larger tumor size (p=0.0276) were observed in the upstaged patients. Multivariable analysis revealed that tumor size and positive serum CEA were independently associated with pathologic upstaging. When tumor size was greater than 10mm, patients with positive serum CEA (>2.0 ng/ml) showed a significantly higher incidence of pathologic upstaging (29.2%) than the rest (15.5%, p=0.0461).

CONCLUSION

Clinically defined peripheral stage IA NSCLC should be carefully indicated for a lesser resection when positive serum CEA and/or tumors greater than 10mm in size are observed.

Risk of recurrence after surgical resection of small-sized invasive lung adenocarcinoma

OBJECTIVE

It has been reported that small-sized invasive lung adenocarcinomas, i.e., those classified as type C through type F according to Noguchi's classification, may also recur even after complete resection. We evaluated the prognostic value of molecular biologic markers (apoptosis, Ki-67, p53, epidermal growth factor) and clinicopathological factors in patients with small-sized invasive lung adenocarcinomas.

METHODS

The clinical records of all patients who had had a peripheral adenocarcinoma surgically resected between 1996 and 2002, and histologically diagnosed as type C through type F according to Noguchi's classification were retrospectively reviewed. The apoptotic index (AI) was determined by the triphosphate biotin nick end-labeling method and the expression of Ki-67, aberrant p53 protein and epidermal growth factor receptor was determined by immunohistochemical staining.

RESULTS

Data from 28 patients who had been followed up for a mean period of 41.8 months (range: 16 to 89 months) were evaluated. During the follow-up period, recurrence was seen in 6 patients. The log-rank test showed that AI was a significant predictor of cancer recurrence. The 5-year disease-free survival rate of the 10 patients in the high AI group (AI > 0.3%) was 100%; while that of the 18 patients in the low AI group (AI < or = 0.3%) was 50.5% (p = 0.036). None of the other molecular biologic markers or clinicopathological factors were found to be a significant predictor of cancer recurrence.

CONCLUSION

Peripheral small-sized invasive lung adenocarcinomas with a low AI carry an increased risk of distant metastases, indicating that adjuvant chemotherapy after complete resection might be needed.

Visceral pleural invasion in lung cancer: recognizing histologic parameters that impact staging and prognosis

Visceral pleural involvement (VPI) is a critical component in the staging of non-small cell lung carcinoma (NSCLC). Tumors < or =3 cm that involve the visceral pleura are classified as T2 lesions, underscoring the prognostic significance of this histologic parameter. Accurate staging of small NSCLCs depends on appropriately assessing the presence or absence of VPI. Elastic stains can be instrumental in detecting disruptions of the visceral pleural elastic layer by tumor, a finding that has prognostic and staging implications similar to tumor that is present on the visceral pleural surface.

Prognostic suggestion in the evaluation of solid component in poorly differentiated adenocarcinoma of the lung

Pulmonary adenocarcinoma composed of pure or predominant solid components is reported to be a highly malignant tumor. However, the existence of solid components and its connection with biological behavior have not been well documented. To answer this question, we histologically subclassified poorly differentiated adenocarcinoma (P/D Ad Ca) into solid type and non-solid type, and compared the biological behavioral characteristics.

MATERIAL AND METHODS

All histological specimens of surgically resected primary lung carcinoma diagnosed as P/D Ca or large cell carcinoma in Nippon Medical School Hospital were re-evaluated according to the 1999 WHO manual. The cases re-evaluated as P/D Ad Ca were further divided into solid type and non-solid type according to our original definition: the solid type contains solid components where a glandular structure is not recognized in more than one high-power field, while in the non-solid type, a small glandular structure is observed in every high-power field. The differences in the occurrence of lymph node metastasis were assessed by Fisher's exact test.

RESULTS

Among 109 cases satisfying both histological and clinical investigation, 45 cases were re-evaluated as P/D Ad Ca; solid type (n=22), and non-solid type (n=23). Lymph node metastases occurred at a higher rate in the solid type than in the non-solid type (p<0.01).

CONCLUSION

Patients with solid type Ad Ca have reached a more advanced stage than patients having non-solid type due to high metastatic rate to lymph nodes. These results suggest that we should not overlook solid components even if the solid components are the focal lesion. This sub-typing alerts clinicians to survey metastases, and may contribute to therapeutic strategies in the future.

Lymph node metastasis, recurrence, and prognosis in small peripheral lung adenocarcinoma. Analysis based on replacement

OBJECTIVE

We studied clinical and pathological features of small peripheral adenocarcinoma of the lung, focusing on tumor typing based on Noguchi's classification of small adenocarcinoma and determining whether these tumors grew by replacing alveolar lining cells.

METHODS

Subjects were 51 patients with small peripheral adenocarcinoma 2 cm or less in diameter resected between 1994 and 2001. Mediastinal and hilar lymph node dissection was done in 37 (72.5%). Patients were divided into 2 groups by replacement or nonreplacement tumors. We compared patient profiles, lymph node involvement, and recurrence and survival patterns.

RESULTS

No significant difference was seen between groups in mean age, surgical procedure, or primary tumor location. Women predominated in replacement tumors at 71% vs 41%, p = 0.04. The incidence of lymph node metastasis at 40% vs 4.5%, p = 0.007 and distant metastasis at 47% vs 2.9%, p < 0.001 was significantly higher in nonreplacement than replacement tumors. Replacements tumor thus showed significantly better disease-free survival at 95% vs 53%, p < 0.001, and overall 3-year survival at 95.4% vs 62.7% than did nonreplacement tumors.

CONCLUSION

We found distant metastasis and lymph node involvement to be more frequent in nonreplacement than replacement small peripheral adenocarcinoma, on suggesting that pretreatment tumor typing and accurate nodal status determination are essential to improve disease staging.