Surgical treatment of lung cancer with adjacent lobe invasion in relation to fissure integrity

Adjacent lobe invasion of T2 tumor in non-small cell lung cancer has T3 disease-like survival fissure invasion: T2 or T3?

Controversy still exists regarding the staging of non-small cell lung cancer (NSCLC) with adjacent lobe invasion (T-ALI) according to the TNM system in terms of T factor and the appropriate surgical resection method. We performed an analysis to compare the prognosis of T-ALI with T2 and T3 disease and to see the effect of our surgical method for these tumors. Two hundred consecutive patients between January 2012 and November 2020, with anatomical lobectomy for T2 or T3 tumor (Group-1) and non-anatomical lobectomy resection (lobectomy plus wedge resection [LWR]) (Group-2) for T-ALI (T2-ALI and T3-ALI) due to primary NSCLC, who did not have lymph node metastases were analyzed retrospectively. All surgeries were performed by two experienced surgeons who adopted the same surgical technique. Those who underwent additional segmentectomy and bilobectomy due to fissure invasion were excluded from the study. Overall survival rates of all patients were determined and factors affecting survival were evaluated by performing univariate and multivariate analyses. Of the patients with a mean age of 62.2 ± 7.8 years, 175 (87.5%) were male and 25 (12.5%) were female. There were 137 (68.5%) patients in Group 1 and 63 (31.5%) patients in Group 2. The mean tumor size in Group 1 (4.4 ± 1.4 cm) was significantly smaller than that in Group 2 (4.9 ± 1.4 cm) (p = 0.014). When T distribution within the groups was considered, the rate of pathological T3 in Group 1 (33.6%) was significantly lower than that in Group 2 (55.6%) (p = 0.005). While the 5-year overall survival rate was 70.1% in Group 1, it was 50.6% in Group 2 (p = 0.022). When tumors were grouped as T2, T2-ALI, T3, and T3-ALI according to T factor, the 5-year overall survival rates were 71.4% and 67.8% in T2 and T3 tumors, respectively, and 49.2% and 51.5% in T2-ALI and T3-ALI tumors, respectively. In the multivariate analysis of these four groups, the overall survival rates for T2-ALI and T3-ALI were significantly lower than those of T2 tumors (p = 0.046 and p = 0.025, respectively). In the analysis made between the T2 tumor group and the new T3 group (T2-ALI, T3, T3-ALI), which was formed by upgrading T2-ALI tumors to the T3 group, T2 tumors were found to have a significantly better survival rate (p = 0.019). The disease-free survival of pT2 patients and new T3 group patients was statistically significant, 63.7% and 45.7%, respectively (p = 0.050). Our results suggest that LWR for T-ALI can be performed with acceptable oncologic outcomes when compared to anatomical lobectomy. T2-ALI has a worse overall survival than T2 tumor and offers a similar prognosis to T3. Given this situation, it is more appropriate to classify T2-ALI as T3. Further studies based on larger series are needed to confirm these preliminary data.

Computed tomography-guided microwave ablation for the treatment of non-small cell lung cancer patients with and without adjacent lobe invasion: A comparative study

BACKGROUND

The aim of the study was to explore the outcomes of computed tomography-guided microwave ablation (MWA) in non-small cell lung cancer (NSCLC) patients with adjacent lobe invasion (ALI), and to compare the outcomes of ALI-NSCLC and non-ALI NSCLC patients after MWA.

METHODS

A total of 319 NSCLC patients and 366 tumors treated with MWA were included in the study, comprising 34 ALI-NSCLC patients and 285 non-ALI NSCLC patients. Complications, local recurrence rates, progression-free survival (PFS), and overall survival (OS) were compared. Logistic regression analyses were used to investigate the correlation between ALI and the occurrence of pneumothorax after MWA.

RESULTS

The mean tumor diameter of ablated tumors was 3.6 ± 2.2 cm. There were 95 (29.8%) NSCLC patients in which pneumothorax occurred after MWA, and all patients recovered. Of these, the ALI group had a significantly higher incidence rate of pneumothorax than the non-ALI group (52.9% vs. 27.0%, p = 0.002). The median PFS and OS for the ALI group were 12.0 ± 10.2 and 15.5 ± 9.5 months, respectively, and that of the non-ALI group were 13.0 ± 10.6 and 17.0 ± 11.1 months, respectively, and no significant difference was found in PFS (p = 0.329) nor OS (p = 0.394) between the two groups. Local recurrence rates for ALI and non-ALI groups were 29.4% and 20.7%, respectively, and no significant difference was found (p = 0.244). Logistic regression analyses revealed that ALI can increase the risk of pneumothorax (hazard ratio [HR], 2.867; p = 0.012).

CONCLUSIONS

MWA is an effective and safe approach for ALI-NSCLC treatment. Although ALI can increase the risk of pneumothorax, ALI-NSCLC patients reveal a comparable outcome to non-ALI NSCLC patients after MWA.

Future Perspectives on the TNM Staging for Lung Cancer

Since its conception by Pierre Denoix in the mid-20th century, the tumor, node, and metastasis (TNM) classification has undergone seven revisions. The North American database managed by Clifton Mountain was used to inform the 2nd to the 6th editions, and an international database collected by the International Association for the Study of Lung Cancer, promoted by Peter Goldstraw, was used to inform the 7th and the 8th editions. In these two latest editions, it was evident that the impact of tumor size was much greater than it was suggested in previous editions; that the amount of nodal disease had prognostic relevance; and that the number and location of the distant metastases had prognostic implications. However, the TNM classification is not the only prognostic factor. Data are being collected now to inform the 9th edition of the TNM classification, scheduled for publication in 2024. Patient-, environment-, and tumor-related factors, including biomarkers (genetic biomarkers, copy number alterations, and protein alterations) are being collected to combine them in prognostic groups to enhance the prognosis provided by the mere anatomic extent of the tumor, and to offer a more personalized prognosis to an individual patient. International collaboration is essential to build a large and detailed database to achieve these objectives.