Mediastinal lymph node dissection for non-small cell lung cancer

Sampling versus systematic full lymphatic dissection in surgical treatment of non-small cell lung cancer

The extent of mediastinal lymph node assessment during surgery for non-small cell cancer remains controversial. Different techniques are used, ranging from simple visual inspection of the unopened mediastinum to an extended bilateral lymph node dissection. Furthermore, different terms are used to define these techniques. Sampling is the removal of one or more lymph nodes under the guidance of pre-operative findings. Systematic (full) nodal dissection is the removal of all mediastinal tissue containing the lymph nodes systematically within anatomical landmarks. A Medline search was conducted to identify articles in the English language that addressed the role of mediastinal lymph node resection in the treatment of non-small cell lung cancer. Opinions as to the reasons for favoring full lymphatic dissection include complete resection, improved nodal staging and better local control due to resection of undetected micrometastasis. Arguments against routine full lymphatic dissection are increased morbidity, increase in operative time, and lack of evidence of improved survival. For complete resection of non-small cell lung cancer, many authors recommend a systematic nodal dissection as the standard approach during surgery, and suggest that this provides both adequate nodal staging and guarantees complete resection. Whether extending the lymph node dissection influences survival or recurrence rate is still not known. There are valid arguments in favor in terms not only of an improved local control but also of an improved long-term survival. However, the impact of lymph node dissection on long-term survival should be further assessed by large-scale multicenter randomized trials.

[From the surgical field to the microscope. A new tool to identify the lymph node specimens in oncologic surgery]

Oncologic surgery and pTNM staging require systemic removal of the locoregional lymphnodes. While the optimal extent and therapeutical and/or prognostic value of the lymphadenectomy/sampling are debated organ by organ and (sub)speciality by (sub)speciality, relevance of the lymphnode sytem-tumor concept itself is beyond doubt. Loss of information and existence of traps on the "surgical field-microscope" pathway is an international phenomenon, calling for solution. An integrated sterile and disposable lymphnode tray system is presented here for applications in the different fields of cancer surgery of the upper GI tract, retroperitoneum (gynecology, urology) and ear-nose-throat surgery.

Complete mediastinal lymphadenectomy: the core component of the multidisciplinary therapy in resectable non-small cell lung cancer

There is a great deal of concern about metastasis of lung cancer to regional lymph nodes, due partly to the work of groups of thoracic surgeons in Japan and North America beginning in the 1970s. The classification of regional lymph node stations for lung cancer staging published by Mountain and Dresler has been widely adopted for more than ten years. Anatomic landmarks for 14 levels of intrapulmonary, hilar, and mediastinal lymph nodes stations are designated. Skip transfer and occult lymph node metastasis, confirmed by studies regarding the mode of spread of intrathoracic lymphatic metastasis, are two theoretical bases for complete mediastinal lymphadenectomy of lung cancer. However, whether or not the degree of the dissection influences prognosis, the role of systematic nodal dissection (SND) vs mediastinal lymph node sampling (MLD) in resectable non-small cell lung cancer (NSCLC) remains controversial. A systematic literature search was performed to identify relevant reports, making full use of the 'Cited by,' 'Related Records,' 'References,' and 'Author Index' functions in the PubMed and ISI Web of Science databases. This paper presents a review of the role of mediastinal lymph node distribution and methods of determining suitability for hilar and mediastinal lymphadenectomy based on the four subsets of stage IIIA-N2, balancing the cost vs effect of mediastinal lymph node dissection in resectable NSCLC, focusing on the stage migration bias in clinical trials comparing SND and MLS, recommending a reasonable node dissection sequence, improving the prospects for the perioperative anti-tumor therapy based on mediastinal lymphadenectomy, and evaluating the various preoperative staging techniques. Finally, we believe that, besides the role of complete resection and accurate staging, the complete mediastinal lymphadenectomy is the core component of the lung cancer multidisciplinary therapy, and suggest that the values of lymphadenectomy should be further assessed using decision-tree analysis based on large-scale prospective randomized trials and pooled analysis to evaluate the costs vs effects.

Commonly encountered difficulties in pathologic staging of lung cancer

CONTEXT

Lung cancer is the leading cause of cancer mortality worldwide. Despite technological, therapeutic, and scientific advances, most patients present with incurable disease and a poor chance of long-term survival. For those with potentially curable disease, lung cancer staging greatly influences therapeutic decisions. Therefore, surgical pathologists determine many facets of lung cancer patient care.

OBJECTIVE

To present the current lung cancer staging system and examine the importance of mediastinal lymph node sampling, and also to discuss particularly confusing and/or challenging areas in lung cancer staging, including assessment of visceral pleura invasion, bronchial and carinal involvement, and the staging of synchronous carcinomas.

DATA SOURCES

Published current and prior staging manuals from the American Joint Committee on Cancer and the International Union Against Cancer as well as selected articles pertaining to lung cancer staging and diagnosis accessible through PubMed (National Library of Medicine) form the basis of this review.

CONCLUSIONS

Proper lung cancer staging requires more than a superficial appreciation of the staging system. Clinically relevant specimen gross examination and histologic review depend on a thorough understanding of the staging guidelines. Common sense is also required when one is confronted with a tumor specimen that defies easy assignment to the TNM staging system.

Role of lymphadenectomy in surgical treatment of solid tumors: an update on the clinical data

BACKGROUND

The role of lymphadenectomy as an adjunct of standard excision for treatment of cancer is highly debated and controversial. Standard practice for treatment of solid tumors is resection with regional lymphadenectomy. This surgical concept assumes that cancers grow and spread in an orderly manner, from primary cancer to regional lymph nodes and finally to vital organs. We reviewed randomized trials, published a description of lymphatic anatomy and physiology, and presented data that disputed the role of lymphadenectomy as standard practice. The present review updates the literature and reiterates the concept that lymphadenectomy does not increase survival in the surgical treatment of solid tumors.

METHODS

We reviewed the English-language literature (Medline) for prospective randomized trials and nonrandomized reports, as well as retrospective studies addressing the role of lymphadenectomy in cancers of the esophagus, lung, stomach, pancreas, breast, and skin (melanoma) reported between 2000 and 2006.

RESULTS

This extensive review demonstrates that there are few prospective randomized trials assessing patient survival with solid tumors that contrast resection with or without lymphadenectomy. However, there was at least one, and for some cancers more than one, prospective randomized trial for each organ site studied, and the data demonstrate no statistically significant difference in overall survival of patients treated with or without lymphadenectomy. Most nonrandomized and retrospective studies, with a few exceptions, support the conclusions of randomized trials; lymphadenectomy does not improve overall survival in solid tumors. Overall survival is primarily a function of the biological nature of the primary tumor, as evidenced by lymphovascular invasion, lymph node involvement, and other prognostic features.

CONCLUSIONS

This extensive literature review of recent reports indicates that lymphadenectomy does not improve overall survival. Lymph node resection should be conceived in terms of staging, prognosis, and regional control only.