Prognostic significance of proliferative activity in pN2 non-small-cell lung carcinomas and their mediastinal lymph node metastases

The Significance of Skip Mediastinal Lymph Node Metastasis in the Prognosis of Patients with Resected Non-Small-Cell Lung Carcinoma: Is It Really a Better N2 Disease Subtype?

Objective: In this study, we aimed to reveal the prognostic differences between skip and non-skip metastasis mediastinal lymph node (MLN) metastasis.

Methods: A total of 202 patients (179 males and 23 females; mean age, 59.66 ± 9.89 years; range: 29–84 years) who had ipsilateral single-station MLN metastasis were analyzed in two groups retrospectively between January 2009 and December 2017: “skip ipsilateral MLN metastasis” group (sN2) (n = 55,27.3%) [N1(–), N2(+)], “non-skip ipsilateral MLN metastasis” group (nsN2) (n = 147,72.7%) [N1(+), N2(+)].

Results: The mean follow-up was 42.63 ± 34.91 months (range: 2–117 months). Among all patients, and in the sN2 and nsN2 groups, the median overall survival times were 63.5 ± 4.56, 68.8 ± 7, and 59.3 ± 5.35 months, respectively, and the 5-year overall survival rates were 38.2%, 46.3%, and 36.4%.

Conclusion: Skip metastasis did not take its rightful place in TNM classification; thus, further studies will be performed. To detect micrometastasis, future studies on skip metastasis should examine non-metastatic hilar lymph nodes (LNs) through staining methods so that heterogeneity in patient groups can be avoided, that is, to ensure that only true skip metastasis cases are included. Afterwards, more accurate and elucidative studies on skip metastasis can be achieved to propound its prognostic importance in the group of N2 disease.

Prognostic factors for survival in patients with completely resected pN2 non-small-cell lung cancer

BACKGROUND

This study examined the incidence of pathologic N2 (pN2) non-small-cell lung cancer (NSCLC) and prognostic factors affecting survival of these patients.

METHODS

A total of 119 patients who underwent surgery for NSCLC (lobectomy and pneumonectomy) between January 2008 and December 2016 were evaluated retrospectively. The patients with pN2 included in this study were assessed in two groups; single pN2 and multiple pN2.

RESULTS

The most common type of resection was lobectomy (56.3%). Ninety-four patients (79%) received adjuvant therapy. Eighty-six patients (72.3%) had single-station pN2 and 33 (27.7%) had multiple pN2. The 5-year survival rates were 29.3% overall, 38.6% in single-station pN2, and 11% in multiple-station pN2 (hazard ratio [HR]: 0.581, p = .037). There was no statistically significant difference in 5-year survival rates between patients with pN1N2 and those with pN0N2 involvement (39.1% vs. 37.1%) (p = .625). Not receiving adjuvant therapy was associated with poor survival prognosis (HR: 8.2 p < .001). The 5-year survival rate was 36.2% among patients with pN2 involvement with 2 or more positive lymph nodes and 19.5% among those with fewer than 2 positive lymph nodes (HR: 0.83, p = .463).

CONCLUSIONS

The most significant prognostic factors associated with survival were pN2 status. Non-skip metastases (pN1N2) and positive lymph node count were not associated with prognosis.

Metastatic Patterns of Mediastinal Lymph Nodes in Small-Size Non-small Cell Lung Cancer (T1b)

Background: Lymph node metastasis (LNM) status is critical to the treatment. Fewer studies has focused on LNM in patients with small-size non-small cell lung cancer (NSCLC). This study aims to investigate clinicopathological characteristics associated with skip N2 (SN2) and non-skip N2 (NSN2) metastasis, and their metastatic patterns in NSCLC with tumor size of 1–2 cm.

Methods: We reviewed the records of NSCLC patients with tumor size of 1–2 cm who underwent lobectomy with systematic lymph node dissection (LND) between January 2013 and June 2019. Clinical, radiographical, and pathological characteristics were compared among N1, SN2, and NSN2 groups. Metastatic patterns of mediastinal lymph node were analyzed based on final pathology.

Results: A total of 63 NSCLC patients with tumor size of 1–2 cm were staged as pN2, including 25 (39.7%) SN2 and 38 (60.3%) NSN2. The incidence rates of SN2 and NSN2 were 2.8% (25/884) and 4.3% (38/884), respectively. For all clinicopathological characteristics, no significant difference was observed among the groups of N1, SN2, and NSN2. For the tumor located in each lobe, specific nodal drainage stations were identified: 2R/4R for right upper lobe; 2R/4R and subcarinal node (#7) for right middle lobe and right lower lobe; 4L and subaortic node (#5) for left upper lobe; #7 for left lower lobe. However, there were still a few patients (10.9%, 5/46) had the involvement of lower zone for tumors of upper lobe and the involvement of upper zone for lower lobe.

Conclusions: SN2 occurs frequently in patients with small-size NSCLC. Whether lobe-specific selective LND is suitable for all small-size patients deserves more studies to confirm. Surgeons should be more careful when performing selective LND for tumors located in the lower and upper lobes.

Single-station skip-N2 disease: good prognosis in resected non-small-cell lung cancer (long-term results in skip-N2 disease)

OBJECTIVES

Pathological N2 (pN2) involvement has a negative impact on prognosis in patients operated on due to non-small-cell lung cancer (NSCLC). pN2 disease may cause skip (pN0N2) or non-skip (pN1N2) metastases with pathological N1 (pN1) involvement. The effect of pN2 subgroups on prognosis is still controversial. We analysed the effect of pN1 disease and single-station pN2 disease subgroups on survival outcomes.

METHODS

The medical records of patients who underwent anatomical lung resection due to NSCLC at a single centre between January 2007 and January 2017 were prospectively collected and retrospectively analysed. Operative mortality, sublobar resection, Stage IV disease, incomplete resection and carcinoid tumour were considered exclusion criteria. After histopathological examination, the prognosis of patients with pN1, pN0N2 and pN1N2 was compared statistically. Univariable and multivariable analyses were made to define independent risk factors for overall survival rates.

RESULTS

The mean follow-up time for 358 patients with 228 pN1 disease (63.7%), 59 pN0N2 disease (16.5%) and 71 pN1N2 disease (19.8%) was 40.4 ± 30.4 months. Median and 5-year overall survival rates for pN1, pN0N2 and pN1N2 diseases were 73.6 months [95% confidence interval (CI) 55.5-91.7] and 54.1%, 60.3 months (95% CI 26.8-93.8) and 51.2%, 20.8 months (95% CI 16.1-25.5) and 21.5%, respectively. The survival CIs of pN1 and pN0N2 diseases were similar, and the survival rates of these 2 groups were significantly better than those with pN1N2 (P < 0.001, P = 0.001, respectively). In multivariable analysis, patients over the age of 60 [hazard ratio (HR) 2.13, P < 0.001], patients not receiving adjuvant therapy (HR 1.52, P = 0.01) and patients with pN1N2 disease (HR 2.91, P < 0.001) had a poor prognosis.

CONCLUSIONS

Advanced age, not receiving adjuvant therapy and having pN1N2 disease are negative prognostic factors in patients with nodal involvement who underwent curative resection due to NSCLC. The overall survival and recurrence-free survival rates of pN1 disease and single-station pN0N2 disease are similar, and they have significantly better survival rates than pN1N2 disease. Based on these results, surgical treatment may be considered an appropriate choice in patients with histopathologically diagnosed single-station skip-N2 disease.

Immunophenotypic features of metastatic lymph node tumors to predict recurrence in N2 lung squamous cell carcinoma

Patients with mediastinal lymph node metastasis (N2) in squamous cell carcinoma (SqCC) of the lung have poor prognosis after surgical resection of the primary tumor. The aim of this study was to clarify predictive factors of the recurrence of pathological lung SqCC with N2 focusing on the biological characteristics of both cancer cells and cancer-associated fibroblasts (CAFs) in primary and metastatic lymph node tumors. We selected 64 patients with pathological primary lung N2 SqCC who underwent surgical complete resection and investigated the expressions of four epithelial–mesenchymal transition-related markers (caveolin, clusterin, E-cadherin, ZEB2), three cancer stem cell-related markers (ALDH-1, CD44 variant6, podoplanin) of cancer cells, and four markers of CAFs (caveolin, CD90, clusterin, podoplanin) in both primary and matched metastatic lymph node tumors in the N2 area. In the primary tumors, the expressions of all the examined molecules were not related to recurrence. However, in the metastatic lymph node tumors, high clusterin and ZEB2 expressions in the cancer cells and high podoplanin expression in the CAFs were significantly correlated with recurrence (P = 0.03, 0.04, and 0.007, respectively). In a multivariate analysis, only podoplanin expression in the CAFs in metastatic lymph node tumors was identified as a significantly independent predictive factor of recurrence (P = 0.03). Our study indicated that the immunophenotypes of both cancer cells and CAFs in metastatic lymph node tumors, but not primary tumors, provide useful information for predicting the recurrence of pathological N2 lung SqCC.

UFT (tegafur and uracil) as postoperative adjuvant chemotherapy for solid tumors (carcinoma of the lung, stomach, colon/rectum, and breast): clinical evidence, mechanism of action, and future direction

UFT (tegafur and uracil) is an oral anticancer drug that has been developed in Japan. Owing to its mild toxicity profile, UFT can be suitable in an adjuvant setting following a complete tumor resection, whereas its direct antitumor effect achieved may be insufficient for advanced unresectable disease. Therefore, a variety of adjuvant chemotherapy trials with UFT have been conducted, and results of well-designed randomized controlled trials have recently shown a survival benefit of postoperative UFT treatment in resected lung, gastric, colorectal, and breast cancer. In the present article, postoperative adjuvant trials with UFT-containing chemotherapy are reviewed, and the mechanism of action and future directions are also discussed.

Prognostic implications of cell cycle-related proteins in primary resectable pathologic N2 nonsmall cell lung cancer

BACKGROUND

Patients who have pathologic N2 (pN2) nonsmall cell lung cancer (pN2 NSCLC) represent a heterogeneous group with regard to prognosis and treatment. Molecular features of NSCLC seem to be of interest. For the current study, to select an appropriate therapeutic strategy for each patient, patients with N2 NSCLC were stratified into homogenous subgroups according to the expression profiles of cell cycle-related markers.

METHODS

The expression levels of retinoblastoma protein (pRb), cyclin D1, p16, p53, and p21 proteins and values of the Ki-67 labeling index were evaluated in 61 primary surgically resected tumor specimens from patients with pN2 NSCLC using immunohistochemistry. The prognostic impact of these markers on overall survival was analyzed in both univariate and multivariate analyses.

RESULTS

In univariate analysis, p21, p16, and Ki-67 were correlated significantly with survival. In multivariate analysis, only p21 and p16 influenced survival. Indeed, the group of patients with pN2 NSCLC who were positive for p21 and p16 had the most favorable overall survival (P = .001) and were correlated significantly with the clinical lymph node (cN) status (cN2 disease; P = .008). Moreover, no significant difference in survival was observed between patients with cN0/cN1 disease and patients with cN2 disease within the group (P = .4333).

CONCLUSIONS

Loss of control of cell-cycle checkpoints is a common occurrence in pN2 NSCLC. Functional cooperation between different cell-cycle regulators constitutes another level of regulation in cell growth control and tumor suppression. Preoperative patients with pN2 NSCLC, even those with cN2 disease, who have positive p21 and p16 protein expression in their primary tumors are expected to have a favorable postoperative prognosis and may be candidates for primary resection.

Analysis of risk factors for skip lymphatic metastasis and their prognostic value in operated N2 non-small-cell lung carcinoma

BACKGROUND

The aim of this study is to report a series and to analyze risk factors for skip lymphatic metastasis an their prognostic value in operated N2 non-small-cell lung carcinoma.

METHODS

From 1997 to 2002, 142 patients classified pN2 were included in the study. Tumours were classified according to the TNM classification. Skips metastases were defined by the cases of N2 disease without lobar and interlobar and hilar lymph node involvement. A skip (+) and a skip (-) group were defined. Characteristics of tumours, ganglionar involvement and survival were analysed in both groups.

RESULTS

Forty-two patients fulfilled the criteria for skip metastasis. The average number of mediastinal lymph nodes resected by patient was similar in both groups, whereas more intrapulmonary nodes were dissected in the skip (-) group (4.7 +/- 3 vs 3 +/- 3; p < 0.002). The ratio of involved to resected lymph nodes was 0.47 +/- 0.27 in the skip (-) group vs 0.23 +/- 0.20 in the skip (+) group (p < 0.0001). In the skip (+) group, 85% of the patients presenting with a right upper lobe tumour had involvement of the superior mediastinal lymph nodes against 40% in the skip (-) group. The 5-year survival rate was 48% in the skip (-) group vs 37% in the skip (+) group (p = 0.49). In multivariate analysis, incomplete resection, tumour size, extended resection and pT were significant prognostic factors.

CONCLUSIONS

Skip metastasis are frequent in non-small-cell lung cancer and complete dissection of hilar and mediastinal lymph nodes should remain the surgical standard procedure for this disease. However, skip metastasis are not an independent prognostic factor in survival.

Results of Initial Operations in Non–Small Cell Lung Cancer Patients With Single-Level N2 Disease

BACKGROUND

There is still debate regarding the use of surgery in the management of non-small cell lung cancer patients with N2 disease. The primary aim of the present study was analysis of the results of initial operations in non-small cell lung cancer patients with single-level N2 disease.

METHODS

Ninety-four patients with the disease who underwent initial surgery consisting of complete resection of the primary site plus systematic lymphadenectomy were examined. We also immunohistochemically examined lymphatic vessel density and vascular endothelial growth factor-C expression.

RESULTS

The overall 5- and 10-year survival rates for the 94 patients were 27.1% and 12.1%, respectively, with a median survival of 22 months. When stratified by skipping status, the 5-year survival rates for the patients in skip-N2 and non-skip-N2 groups were 33.4% and 19.8%, respectively (p = 0.0189). Skip metastasis, T factor, subcarinal lymph node metastasis, and adjuvant chemotherapy were recognized as independent prognostic indicators. In both skip-N2 and non-skip-N2 groups, distant relapse was the dominant pattern of recurrence. Although the peritumoral lymphatic vessel density was associated with vascular endothelial growth factor-C expression in tumors, the lymphangiogenic profile appeared to be different between skip-N2 and non-skip-N2 tumors, suggesting different nodal metastatic process.

CONCLUSIONS

Lung cancer patients with single-level N2 disease are an oncologically heterogeneous cohort. Although further studies involving randomized comparisons are required, the poor outcomes found here indicate that the initial operation has yet to be validated for patients with this disease.

Skip metastasis in nonsmall cell lung carcinoma

BACKGROUND

Skip metastasis to mediastinal lymph nodes is a prognostic factor for patients with nonsmall cell lung carcinoma (NSCLC). Little is known about the biologic behavior of tumors with noncontinuous spread to the mediastinal lymph nodes. In patients with pN2 skip metastases, micrometastases to N1 lymph nodes, which only mimic skip metastases, have not been investigated.

METHODS

In a retrospective study, the authors analyzed the primary tumor specimens from 45 patients with pN2 NSCLC (18 patients had squamous cell carcinomas, 23 had adenocarcinomas, and 4 had large cell carcinomas). They immunohistochemically evaluated the expression of p21, p53, MUC-1, Bcl-2, c-ErbB-2, and E-cadherin. Survival rates and biomarker expression levels were compared between patients with pN2 disease and infiltration of N1 lymph nodes (without skip metastasis [n = 28]) and patients with pN2 disease without N1 infiltration (with skip metastasis [n = 17]). To evaluate micrometastasis in the pN1 lymph nodes of 17 patients with skip metastases, lymph nodes were stained using the anticytokeratin antibody, AE1/AE3.

RESULTS

The 5-year survival rate of patients with skip metastases was 41%, compared with 14% for patients without skip metastases (P = 0.019). In a multivariate analysis, the incidence of skip metastases did not vary significantly according to gender, age, histology, pT status, or cM status. Three skip-positive patients (17.6%) had micrometastatic tumor involvement of pN1 lymph nodes. After adding these patients to the group of patients without skip metastases, there was still a significant difference in survival between the two groups. p53, MUC-1, c-ErbB-2, and E-cadherin expression levels in primary tumor specimens were not significantly different in patients with continuous metastasis and patients with skip metastases. Patients with skip metastases expressed lower levels of p21 (P = 0.026), whereas Bcl-2 expression levels were considerably higher (P = 0.019) compared with the corresponding levels in patients without skip metastases.

CONCLUSIONS

Patients with NSCLC and pN2 skip metastases have a more favorable prognosis than do patients with pN2 disease without skip metastases. Tumor specimens from these patients exhibit elevated expression of the antiapoptosis gene BCL2 and lower expression levels of p21 relative to patients with pN2 disease without skip metastases. Micrometastases occurred in 3 of 17 (17.6%) patients with pN2 disease and skip metastases diagnosed by routine histopathology.

Prognostic significance of bcl-2 expression in resected pN2 non-small cell lung cancer

AIMS

The prognosis of non-small cell lung cancer with pathologic mediastinal lymph node involvement (pN2) is poor, we wished to study the expression of p53, bcl-2 by immunohistochemistry in a series of such patients.

METHODS

Clinicopathologic factors were investigated in relation to prognosis in 60 patients with resected pN2 non-small cell lung cancer.

RESULTS

The 5-year survival rate was 21.7%. Positive staining for p53, and bcl-2 was found in 29/60 and 12/60, respectively. Patients with bcl-2 positive tumor had a more favorable survival than those with bcl-2 negative tumor (P=0.0054). The expression of p53 was not related to patients' survival. Multivariate analysis showed that Bcl-2 expression and single N2 station were independent prognostic factors.

CONCLUSIONS

Patients with bcl-2 positive tumors may comprise a favorable prognostic subgroup in pN2 non-small cell lung cancer.

Prognostic factors in non-small cell lung cancer: a decade of progress

STUDY OBJECTIVES

To provide a systematic overview of the literature investigating patient and tumor factors that are predictive of survival for patients with non-small cell lung cancer (NSCLC), and to analyze patterns in the design of these studies in order to highlight problematic aspects of their design and to advocate for appropriate directions of future studies.

DESIGN

A systematic search of the MEDLINE database and a synthesis of the identified literature.

MEASUREMENTS AND RESULTS

The database search (January 1990 to July 2001) was carried out combining the MeSH terms prognosis and carcinoma, nonsmall cell lung. Eight hundred eighty-seven articles met the search criteria. These studies identified 169 prognostic factors relating either to the tumor or the host. One hundred seventy-six studies reported multivariate analyses. Concerning 153 studies reporting a multivariate analysis of prognostic factors in patients with early-stage NSCLC, the median number of patients enrolled per study was 120 (range, 31 to 1,281 patients). The median number of factors reported to be significant in univariate analyses was 4 (range, 2 to 14 factors). The median number of factors reported to be significant in multivariate analyses per study was 2 (range, 0 to 6 factors). The median number of studies examining each prognostic factor was 1 (range, 1 to 105 studies). Only 6% of studies addressed clinical outcomes other than patient survival.

CONCLUSIONS

While the breadth of prognostic factors studied in the literature is extensive, the scope of factors evaluated in individual studies is inappropriately narrow. Individual studies are typically statistically underpowered and are remarkably heterogeneous with regard to their conclusions. Larger studies with clinically relevant modeling are required to address the usefulness of newly available prognostic factors in defining the management of patients with NSCLC.