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Non-Small Cell Lung Cancer · Surgical Oncology

CALGB/Alliance 140503

In peripheral stage IA NSCLC ≤2 cm, can sublobar resection replace lobectomy without compromising cancer control?

Population
697 patients with peripheral clinical T1aN0M0 NSCLC ≤2 cm and node-negative disease
Comparison
Sublobar resection versus lobectomy
5-year DFS
63.6% vs 64.1%
Absolute difference −0.5 percentage points; HR 1.01
5-year OS
80.3% vs 78.9%
HR 0.95; non-inferiority was demonstrated

Absolute Effect

NNT: not applicable. This was a non-inferiority trial, so the result should not be reframed as a survival benefit. The clinically relevant advantage of sublobar surgery is preservation of lung function rather than improved survival.

NNH: not quantifiable. No single dominant fixed-time severe-toxicity endpoint supports a defensible NNH. At six months, pulmonary function was modestly better after sublobar resection.

Clinical interpretation

For carefully selected patients with peripheral ≤2-cm node-negative stage IA NSCLC, sublobar resection provides cancer outcomes comparable with lobectomy while preserving more lung tissue. The evidence supports replacing lobectomy in appropriate patients, but it does not establish sublobar surgery as oncologically superior.

Primary source

Altorki NK, et al. N Engl J Med. 2023;388:489–498.

Read the primary publication →

Current-practice context · reviewed 14 October 2026

CALGB 140503 supports sublobar resection as non-inferior to lobectomy for carefully selected peripheral NSCLC no larger than 2 cm when hilar/mediastinal nodes are pathologically confirmed negative. This is not permission to omit adequate margins or nodal staging, and the findings should not be extrapolated to larger, central or node-positive tumours. Operative choice depends on pulmonary reserve, tumour location and multidisciplinary review.

CALGB/Alliance 140503 primary/registry source ↗ · Current guideline guidance ↗