Survival after surgery in stage IA and IB non-small cell lung cancer

Abstract

Rationale: Whether histologic subtype of non-small cell lung cancer (NSCLC) has an important effect on prognosis after surgery is unknown.

Objectives: We hypothesized that we could predict mortality more effectively by integrating precise tumor size and histology rather than relying on conventional staging.

Methods: We used the SEER (Surveillance, Epidemiology, and End Results) registry. Inclusion criteria were as follows: (1) primary squamous cell or adenocarcinoma; (2) potentially curative surgery, defined as a lobectomy or bilobectomy; (3) lymph node dissection performed; and (4) pathologic stage IA or IB.

Measurements and main results: From 1988 to 2000, 7,965 patients were included. For both all-cause and lung cancer-associated mortality, tumor size demonstrated the strongest association (log-rank P < 0.0001 for each). When tumors were small (</=2 cm), lung cancer-associated mortality was similar for adenocarcinoma when compared with squamous cell carcinoma. When tumors were 3 cm or larger in size, lung cancer-associated mortality was higher for adenocarcinoma. The increased risk of lung cancer-associated mortality with adenocarcinoma was more pronounced in those younger than 65 years. Survival prediction using precise size and histology had much better discriminatory power than conventional TNM (tumor-node-metastasis) staging (P = 0.005).

Conclusions: Staging that takes into account size, histology, late recurrence risk, and patient age is more accurate than the current TNM system and is clinically relevant because improved prediction can facilitate better decisions on the use of adjuvant chemotherapy.

Figure 1.

Kaplan-Meier curves for mortality due to lung cancer in patients postlobectomy (A) according to size (log-rank p < 0.0001) and (B) according to histology, either adenocarcinoma (red) or squamous cell carcinoma (black). (C) Classified according to size for squamous cell carcinoma (log-rank P < 0.0001). (D) Classified according to size for adenocarcinomas (log-rank P < 0.0001).

Figure 1.

Kaplan-Meier curves for mortality due to lung cancer in patients postlobectomy (A) according to size (log-rank p < 0.0001) and (B) according to histology, either adenocarcinoma (red) or squamous cell carcinoma (black). (C) Classified according to size for squamous cell carcinoma (log-rank P < 0.0001). (D) Classified according to size for adenocarcinomas (log-rank P < 0.0001).

Figure 1.

Kaplan-Meier curves for mortality due to lung cancer in patients postlobectomy (A) according to size (log-rank p < 0.0001) and (B) according to histology, either adenocarcinoma (red) or squamous cell carcinoma (black). (C) Classified according to size for squamous cell carcinoma (log-rank P < 0.0001). (D) Classified according to size for adenocarcinomas (log-rank P < 0.0001).

Figure 1.

Kaplan-Meier curves for mortality due to lung cancer in patients postlobectomy (A) according to size (log-rank p < 0.0001) and (B) according to histology, either adenocarcinoma (red) or squamous cell carcinoma (black). (C) Classified according to size for squamous cell carcinoma (log-rank P < 0.0001). (D) Classified according to size for adenocarcinomas (log-rank P < 0.0001).

Figure 2.

Kaplan-Meier curves for mortality due to lung cancer in patients postlobectomy stratified according to size. Red represents adenocarcinoma, black indicates squamous cell carcinoma. (A) Tumors ⩽2 cm in size (log-rank P = 0.76); (B) tumors >2cm but ⩽3cm in size (log-rank P = 0.23); (C) tumors >3 cm but ⩽4 cm in size (log-rank P = 0.007); (D) tumors >4 cm in size (log-rank P = 0.10).

Figure 2.

Kaplan-Meier curves for mortality due to lung cancer in patients postlobectomy stratified according to size. Red represents adenocarcinoma, black indicates squamous cell carcinoma. (A) Tumors ⩽2 cm in size (log-rank P = 0.76); (B) tumors >2cm but ⩽3cm in size (log-rank P = 0.23); (C) tumors >3 cm but ⩽4 cm in size (log-rank P = 0.007); (D) tumors >4 cm in size (log-rank P = 0.10).

Figure 2.

Kaplan-Meier curves for mortality due to lung cancer in patients postlobectomy stratified according to size. Red represents adenocarcinoma, black indicates squamous cell carcinoma. (A) Tumors ⩽2 cm in size (log-rank P = 0.76); (B) tumors >2cm but ⩽3cm in size (log-rank P = 0.23); (C) tumors >3 cm but ⩽4 cm in size (log-rank P = 0.007); (D) tumors >4 cm in size (log-rank P = 0.10).

Figure 2.

Kaplan-Meier curves for mortality due to lung cancer in patients postlobectomy stratified according to size. Red represents adenocarcinoma, black indicates squamous cell carcinoma. (A) Tumors ⩽2 cm in size (log-rank P = 0.76); (B) tumors >2cm but ⩽3cm in size (log-rank P = 0.23); (C) tumors >3 cm but ⩽4 cm in size (log-rank P = 0.007); (D) tumors >4 cm in size (log-rank P = 0.10).

Figure 3.

Kaplan-Meier curves for death due to lung cancer in patients postlobectomy stratified according to size and age. Red represents adenocarcinoma, black indicates squamous cell carcinoma. Left side panels show those subjects ⩽65 years of age at time of diagnosis; right side, those >65 years of age. All P values are log-rank tests. (A) Tumors ⩽2 cm in size; age ⩽65, P = 0.71; age >65, P = 0.78. (B) Tumors >2 cm but ⩽3cm in size; age ⩽65, P = 0.09; age >65, P = 0.66. (C) Tumors >3 cm but ⩽4 cm in size; age ⩽65, P = 0.0003; age >65, P = 0.39. (D) Tumors >4 cm in size; age <65, P = 0.08; age >65, P = 0.15.

Figure 3.

Kaplan-Meier curves for death due to lung cancer in patients postlobectomy stratified according to size and age. Red represents adenocarcinoma, black indicates squamous cell carcinoma. Left side panels show those subjects ⩽65 years of age at time of diagnosis; right side, those >65 years of age. All P values are log-rank tests. (A) Tumors ⩽2 cm in size; age ⩽65, P = 0.71; age >65, P = 0.78. (B) Tumors >2 cm but ⩽3cm in size; age ⩽65, P = 0.09; age >65, P = 0.66. (C) Tumors >3 cm but ⩽4 cm in size; age ⩽65, P = 0.0003; age >65, P = 0.39. (D) Tumors >4 cm in size; age <65, P = 0.08; age >65, P = 0.15.

Figure 3.

Kaplan-Meier curves for death due to lung cancer in patients postlobectomy stratified according to size and age. Red represents adenocarcinoma, black indicates squamous cell carcinoma. Left side panels show those subjects ⩽65 years of age at time of diagnosis; right side, those >65 years of age. All P values are log-rank tests. (A) Tumors ⩽2 cm in size; age ⩽65, P = 0.71; age >65, P = 0.78. (B) Tumors >2 cm but ⩽3cm in size; age ⩽65, P = 0.09; age >65, P = 0.66. (C) Tumors >3 cm but ⩽4 cm in size; age ⩽65, P = 0.0003; age >65, P = 0.39. (D) Tumors >4 cm in size; age <65, P = 0.08; age >65, P = 0.15.

Figure 3.

Kaplan-Meier curves for death due to lung cancer in patients postlobectomy stratified according to size and age. Red represents adenocarcinoma, black indicates squamous cell carcinoma. Left side panels show those subjects ⩽65 years of age at time of diagnosis; right side, those >65 years of age. All P values are log-rank tests. (A) Tumors ⩽2 cm in size; age ⩽65, P = 0.71; age >65, P = 0.78. (B) Tumors >2 cm but ⩽3cm in size; age ⩽65, P = 0.09; age >65, P = 0.66. (C) Tumors >3 cm but ⩽4 cm in size; age ⩽65, P = 0.0003; age >65, P = 0.39. (D) Tumors >4 cm in size; age <65, P = 0.08; age >65, P = 0.15.

Figure 3.

Kaplan-Meier curves for death due to lung cancer in patients postlobectomy stratified according to size and age. Red represents adenocarcinoma, black indicates squamous cell carcinoma. Left side panels show those subjects ⩽65 years of age at time of diagnosis; right side, those >65 years of age. All P values are log-rank tests. (A) Tumors ⩽2 cm in size; age ⩽65, P = 0.71; age >65, P = 0.78. (B) Tumors >2 cm but ⩽3cm in size; age ⩽65, P = 0.09; age >65, P = 0.66. (C) Tumors >3 cm but ⩽4 cm in size; age ⩽65, P = 0.0003; age >65, P = 0.39. (D) Tumors >4 cm in size; age <65, P = 0.08; age >65, P = 0.15.

Figure 3.

Kaplan-Meier curves for death due to lung cancer in patients postlobectomy stratified according to size and age. Red represents adenocarcinoma, black indicates squamous cell carcinoma. Left side panels show those subjects ⩽65 years of age at time of diagnosis; right side, those >65 years of age. All P values are log-rank tests. (A) Tumors ⩽2 cm in size; age ⩽65, P = 0.71; age >65, P = 0.78. (B) Tumors >2 cm but ⩽3cm in size; age ⩽65, P = 0.09; age >65, P = 0.66. (C) Tumors >3 cm but ⩽4 cm in size; age ⩽65, P = 0.0003; age >65, P = 0.39. (D) Tumors >4 cm in size; age <65, P = 0.08; age >65, P = 0.15.

Figure 3.

Kaplan-Meier curves for death due to lung cancer in patients postlobectomy stratified according to size and age. Red represents adenocarcinoma, black indicates squamous cell carcinoma. Left side panels show those subjects ⩽65 years of age at time of diagnosis; right side, those >65 years of age. All P values are log-rank tests. (A) Tumors ⩽2 cm in size; age ⩽65, P = 0.71; age >65, P = 0.78. (B) Tumors >2 cm but ⩽3cm in size; age ⩽65, P = 0.09; age >65, P = 0.66. (C) Tumors >3 cm but ⩽4 cm in size; age ⩽65, P = 0.0003; age >65, P = 0.39. (D) Tumors >4 cm in size; age <65, P = 0.08; age >65, P = 0.15.

Figure 3.

Kaplan-Meier curves for death due to lung cancer in patients postlobectomy stratified according to size and age. Red represents adenocarcinoma, black indicates squamous cell carcinoma. Left side panels show those subjects ⩽65 years of age at time of diagnosis; right side, those >65 years of age. All P values are log-rank tests. (A) Tumors ⩽2 cm in size; age ⩽65, P = 0.71; age >65, P = 0.78. (B) Tumors >2 cm but ⩽3cm in size; age ⩽65, P = 0.09; age >65, P = 0.66. (C) Tumors >3 cm but ⩽4 cm in size; age ⩽65, P = 0.0003; age >65, P = 0.39. (D) Tumors >4 cm in size; age <65, P = 0.08; age >65, P = 0.15.

Figure 4.

Kaplan-Meier curves for death due to lung cancer in patients postlobectomy according to TNM (tumor-node-metastasis) stage, either stage IA (black) or IB (red) (log-rank P < 0.0001).