Extent of Lymph Node Dissection in Patients with Small-Sized Peripheral Non-Small Cell Lung Cancer during Intentional Segmentectomy

Lymph node dissection in small peripheral lung cancer: Supplemental analysis of JCOG0802/WJOG4607L

OBJECTIVE

The optimal region of lymph node dissection (LND) during segmentectomy in patients with small peripheral non-small cell lung cancer requires clarification. Through a supplemental analysis of the Japan Clinical Oncology Group (JCOG) 0802/West Japan Oncology Group (WJOG) 4607L, we investigated the associated factors, distribution, and recurrence pattern of lymph node metastases (LNMs) and proposed the optimal LND region.

METHODS

Of the 1106 patients included in the JCOG0802/WJOG4607L, 1056 patients with LNDs were included in this supplemental analysis. We investigated the distribution and recurrence pattern of LNMs along with the radiologic findings (with ground-glass opacity, part-solid tumor; without ground-grass opacity component, pure-solid tumor).

RESULTS

The radiologic findings were the only significant factor for LNMs. Of 533 patients with part-solid tumors, 8 (1.5%) had LNMs. Further, only 3 (0.5%) patients had pN2 disease, and no patients had interlobar LNMs from nonadjacent segments. Of the 523 patients with pure-solid tumors, 55 (10.5%) had LNMs, and 28 (5.4%) had pN2 disease. Five patients had metastases to nonadjacent interlobar lymph nodes (LNs). Two (2.0%) patients with S6 tumors had upper mediastinal LNMs. In addition, the incidence of mediastinal LN recurrence in patients with S6 lung cancer was greater in those who underwent selective LND than those who underwent systematic LND (P = .0455).

CONCLUSIONS

Nonadjacent interlobar and mediastinal LND have little impact on pathologic nodal staging in patients with part-solid tumors. In contrast, selective LND is recommended at least for patients with pure-solid tumors.

Lymph node metastasis and tumor-educated immune tolerance: Potential therapeutic targets against distant metastasis

Lymph node metastasis has been shown to positively associated with the prognosis of many cancers. However, in clinical treatment, lymphadenectomy is not always successful, suggesting that immune cells in the tumor and sentinel lymph nodes still play a pivotal role in tumor immunosuppression. Recent studies had shown that tumors can tolerate immune cells through multiple strategies, including tumor-induced macrophage reprogramming, T cells inactivation, production of B cells pathogenic antibodies and activation of regulatory T cells to promote tumor colonization, growth, and metastasis in lymph nodes. We reviewed the bidirectional effect of immune cells on anti-tumor or promotion of cancer cell metastasis during lymph node metastasis, and the mechanisms by which malignant cancer cells modify immune cells to create a more favorable environment for the growth and survival of cancer cells. Research and treatment strategies focusing on the immune system in lymph nodes and potential immune targets in lymph node metastasis were also be discussed.