Prognostic value of T and N in non small cell lung cancer three centimeters or less in diameter.

OBJECTIVE

Peripheral tumors 3 cm or less in diameter are classified T1, T2 when rupturing the visceral pleura, T3 when invading parietal pleura, chest wall, mediastinal pleura or pericardium and T4 when invading vertebra or mediastinal structures. Our objective was to assess the prognostic significance of T and N status according to the size of such tumors.

PATIENTS AND

METHODS

Patients (918) were operated upon between April 1984 and December 1991. Surgery included complete resection and mediastinal lymphadenectomy. Tumors 3 cm or less were studied concerning T, N status, histology and survival.

RESULTS

There were 314 such tumors (T1 = 215, T2 = 64, T3 = 35, T4 = 6); N status was N0 60.2%, N1 21%, N2 18.8%. Global 5-year survival was 52.59%. In case of N0, survival was 64.63%: T1 = 63.76%, T2 = 71.48%, T3 = 45.71%, T4 = 66.6%; which was not significant. There were 48 tumors 1.0 cm or less in diameter (G1), 111 tumors 1.1-2.0 cm in diameter (G2) and 155 tumors 2.1-3 cm in diameter (G3). The incidence of N0, N1 and N2 disease was 77.1, 10.4 and 12.5%, respectively in G1, 64, 18 and 18% in G2, and 52.3, 26.5 and 21.3% in G3. The 5-year survival rate was 62.46% for G1, 52.91% for G2 and 49.36% for G3 (NS). In cases of N1 and N2, survival was 48.41% and 20.2% which was significant (P < 0.05) but differences between each T and each G were not significant.

CONCLUSIONS

Small peripheral cancers spread into mediastinal nodes in 12.5-21.3% of cases, according to the size. This is a warning to perform nodes resections in cases where surgeons intend a videothoracoscopic approach. N2 status is not only an indicator but also a governor of prognosis. Neither T status nor size are determinants of prognosis as far as tumors 3 cm in diameter or less are concerned.