Surgical management or treatment of cancer

as mentioned before it divided into three groups

1- surgical management of the primary tumor

2- surgical management of the regional lymph nodes basin

3- surgical management of distant metastasis

2- Surgical management of the Regional lymph nodes basin which will be discuss

Most neoplasms metastasize via the lymphatics

 Therefore, most onocologic operations have been designed to remove the primary tumor and drainage  lymphatic en bloc

 This type of operative ap­proach is usually undertaken when the lymph nodes draining the primary tumor lie adjacent to the tumor bed, as is the case for colorectal cancer and gastric cancers

For tumors where the regional lymph node basin is not immediately adjacent to the tumor eg,melanomas  lymph node surgery can be performed through 
 separate incision

 Unlike most carcinomas, soft-tissue sarcomas rarely metastasize<5%) to the lymph nodes, therefore lymph node surgery is usually not necessary

It is generally accepted that a formal lymphadenectomy is likely
to minimize the risk of regional recurrence of most cancers. 

For ex­ample, the introduction of total mesorectal excision of rectal cancer been associated with a large decline in local-regional recurrence­ and this procedure has become the new standard of operative management
  On the other hand, there have been two opposing views regarding the role of lymphadenectomy on survival of cancer patients

The traditional Halsted view states that lymph­denectomy is important for staging and survival

The opposing view counters that cancer is systemic at inception and that lymph­adenectomy, although useful for staging does not affect survival

For most cancers, involvement of the lymph nodes is one of the most significant prognostic factors. Interestingly, the number of  lymph nodes removed has been found to have an inverse relationship with overall survival rate in many solid tumors, including breast can­cer, colon cancer, and lung cancer

Although this seems to support the Halsted theory that more extensive lymphadenectomy yielding more nodes reduces the risk of regional recurrence, there may be alternate explanations for the same finding

 For example the surgeon who performs a more extensive lymphadenectomy may obtain wider margins around the tumor, or even provide better over­ all care such as ensuring that patients receive the appropriate ad­juvant therapy or undergo more thorough staging work-up

Al­ternatively, the pathologist may perform a more thorough exam­ination, identifying more nodes and more accurately staging the nodes

The effect of appropriate staging on survival is twofold

 Pa­tients with nodal metastases may be offered adjuvant therapy, im­proving their survival chances

Further the improved staging can improve perceived survival rates through a Will Rogers effect, meaning identifications  of metastases that had formerly been silent and unidentified leads to a stage migration and thus to a perceived improvement in a chance of survival

Clearly the impact of lymphadenectomy on survival will not be easily resolved. Since mini­mizing regional recurrences as much as possible is a goal of cancer treatment, the standard of care remains lymphadenectomy for most tumors
A relatively new development in the surgical management of the clinically negative regional lymph node basin is the introduction of lymphatic mapping technology

 Lymphatic map­ping and sentinel lymph node biopsy were first reported in 1977 by
Cabanas for penile cancer , Morton and colleagues 

 implemented this approach for the treatment of melanoma, and Giuliano and colleagues further adapted the technology to breast cancer

 Now sentinel node biopsy is the standard of care for the management of melanoma and is rapidly becoming the standard of care in breast cancer

Moreover, the utility of sentinel node biopsy is being ex­plored in other cancers such as esophageal, gastric, colon, and head and neck cancers
What are the definition of sentinel lymph node
The first node to receive drainage from the tumor site is termed the sentinel node

 This node is the node most likely to contain metas­tases, if metastases to that regional lymph node basin are present

 The goal of lymphatic mapping and sentinel lymph node biopsy is to identify and remove the lymph node most likely to contain metas­tases in the least invasive fashion

 The practice of sentinel lymph node biopsy followed by selective regional lymph node dissection for patients with a positive sentinel lymph node avoids the morbidity of lymph node dissections in patients with negative nodes

 An ad­ditional advantage of the sentinel lymph node technique is that it directs attention to a single node, allowing more careful analysis of the lymph node most likely to have a positive yield and increasing the accuracy of nodal staging
 two criteria are used to assess the efficacy of a sentinel lymph node biopsy

 the sentinel lymph node identification rate and the false negative rate

 The sentinel lymph node identification rate is the proportion of patients in whom a sentinel lymph node was iden­tified and removed among all patients undergoing an attempted sen­tinel lymph node biopsy

The false-negative rate is the proportion of patients with regional lymph node metastases in whom the sen­tinel lymph node was found to be negative

 False-negative biopsies may be due to identification of the wrong node or to missing the sentinel node (i.e surgical error), or they may be due to the cancer cells establishing metastases not in the first encountered node, but in a second echelon node (i.e., biologic variation

 Alternatively, false-negative biopsies may be due to inadequate histologic evalu­ation of the lymph node

 A sentinel lymph node can be identified in almost 100% of melanoma patients and in 94% of breast can­cer patients

The false-negative rates for sentinel lymph node biopsy in larger series range between 0 and 11% Both increases in the identification rate and decreases in the false-negative rate have been observed as surgeons gain experience with the tech­nique For breast cancer, therefore, it is recommended that until a surgeon documents an identification rate of greater than 90% and a false-negative rate of less than 5%, he or she should continue to perform concomitant axillary dissections

Lymphatic mapping is performed by using isosulfan blue dye, technetium-labeled sulfur colloid or albumin. or a combination of both techniques to detect sentinel nodes

 The combination of blue dye and technetium has been reported to improve the capability of detecting sentinel lymph nodes

The nodal drainage pattern usu­ally is determined with a preoperative lymphoscintogram, and the hot and/or blue nodes are identified with the assistance of a gamma probe and careful nodal basin exploration

 Careful manual palpa­tion is a crucial pan of the procedure to minimize the false-negative rate

 The nodes are evaluated with serial sectioning, hematoxylin and Eosin staining, and immunohistochemical staining with S-I00 and HMB-45 for melanoma and cytokeratin for breast cancer.

In spite of wide spread use of lymphatic mapping, there are still
controversies about some technical aspects such as how many nodes should be removed

 Other controversies that remain in lym­phatic mapping for breast cancer include the roles of lymphoscintig­raphy, internal mammary nodal mapping, and immunohistochem­istry, and the indications for completion of node dissection

The uses of sentinel node biopsy after an excisional biopsy in patients with large breast tumors, in patients who have received preopera­tive chemotherapy and in patients with multicentric disease also have been controversial

 However, it is increasingly apparent that although these patients may have a higher risk for a false-negative sentinel node, the accuracy is still high enough to justify sentinel node biopsy in most patients

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