The sentinel node in anal carcinoma

Feasibility and impact of sentinel lymph node biopsy in patients affected by ano-rectal melanoma

INTRODUCTION

Anorectal melanoma (ARM) is rare and highly lethal neoplasm. It has a poorer prognosis compared with cutaneous ones. Sentinel lymph node biopsy (SLNB) has become the preferred method of nodal staging method for cutaneous melanoma. The role of SLNB for staging of anal melanoma remains unclear. This study investigates SLN identification and biopsy in patients with ARM.

METHODS AND PATIENTS

We present our experience of patients affected by ARM who underwent to SLNB. Clinical workup included digital rectal examination, anoscopy, rigid proctoscopy, total body (computed tomography) CT scan, pelvic magnetic resonance imaging (MRI), and fludeoxyglucose-18-positron emission tomography-CT (FDG-PET-CT) to obtain an adequate pretreatment staging of the patients. Wide local excision and contemporary SLNB were performed to remove primary neoplasm and detect inguinal lymph node metastases.

RESULTS

In total, five female patients, median age 68 years, were included. All were affected by anal melanoma. Detection rate of SLNB was 100% and scintigraphic migration was unilateral in three patients and bilateral in the other two. Definitive inguinal histological exam revealed unilateral metastases in three patients, bilateral metastases in one case, and the presence of isolated neoplastic cells in the remaining case. SLNB allowed a diagnostic upgrading of inguinal metastases in three of five patients (60%), permitting better staging and further appropriate treatment.

CONCLUSIONS

Our experience demonstrates SLN biopsy is a minimally invasive, cost-effective, and rapid procedure for accurately staging patients with clinically occult disease. In fact, SLNB emerges as an appropriate procedural tool to identify patients with occult lymph node metastases who could undergo immune or target therapy, as well as to avoid unnecessary inguinal lymph node dissection for patients who would not benefit.

The Sentinel Node in Anal Carcinoma

Aims and Background

Anal cancer is a rare condition. The inguinal lymph nodes are the most common site of metastasis in this neoplasm. The inguinal lymph node status is an important prognostic indicator and the presence of metastases is an independent prognostic factor for local failure and overall mortality. Depending on the primary tumor size and histological differentiation, metastasis to superficial inguinal lymph nodes occurs in 15-25% of cases.

Methods and Study Design

To evaluate the inguinal lymph node status we performed a search for the sentinel node in a female patient affected by squamous anal carcinoma.

Results

Identification and examination of the sentinel node was positive and postoperative histology showed the presence of bilateral lymph node metastases.

Conclusions

We suggest that examination of the sentinel node in anal cancer could be an efficient way to establish the inguinal lymph node status, which would help the clinician to plan and perform adequate treatment.

Anal cancer - a review

Anal cancer accounts for only 1.5% of gastrointestinal malignancies but this disease has shown a steady increase in incidence particularly in HIV positive males. The understanding of pathophysiology and treatment of anal cancer has changed radically over last thirty years. Risk factors have been identified and organ preservation by chemoradiotherapy has become a standard. This article aims to review the clinical presentation, diagnostic evaluation, and treatment options for anal cancer in the light of current literature.

Value of staging squamous cell carcinoma of the anal margin and canal using the sentinel lymph node procedure: an update of the series and a review of the literature

Background:

Inguinal metastases in patients affected by anal cancer are an independent prognostic factor for local failure and overall mortality. Since 2001, sentinel lymph node biopsy was applied in these patients. This original study reports an update of personal and previous published series, which were compared with Literature to value the incidence of inguinal metastases T-stage related and the overall incidence of false negative inguinal metastases at sentinel node.

Methods:

In all, 63 patients diagnosed with anal cancer submitted to inguinal sentinel node. Furthermore a research in the Pub Med database was performed to find papers regarding this technique.

Results:

In our series, detection rate was 98.4%. Inguinal metastases were evidentiated in 13 patients (20.6%). Our median follow-up was 35 months. In our series, no false negative nodes were observed.

Conclusion:

Sentinel node technique in the detection of inguinal metastases in patients affected by anal cancer should be considered as a standard of care. It is indicated for all T stages in order to select patients to be submitted to inguinal radiotherapy, avoiding related morbidity in negative ones. An overall 3.7% rate of false negative must be considered acceptable.

New approach to anal cancer: Individualized therapy based on sentinel lymph node biopsy

Oncological treatment is currently directed toward a tailored therapy concept. Squamous cell carcinoma of the anal canal could be considered a suitable platform to test new therapeutic strategies to minimize treatment morbidity. Standard of care for patients with anal canal cancer consists of a combination of radiotherapy and chemotherapy. This treatment has led to a high rate of local control and a 60% cure rate with preservation of the anal sphincter, thus replacing surgical abdominoperineal resection. Lymph node metastases represent a critical independent prognostic factor for local recurrence and survival. Mesorectal and iliac lymph nodes are usually included in the radiation field, whereas the inclusion of inguinal regions still remains controversial because of the subsequent adverse side effects. Sentinel lymph node biopsies could clearly identify inguinal node-positive patients eligible for therapeutic groin irradiation. A sentinel lymph node navigation procedure is reported here to be a feasible and effective method for establishing the true inguinal node status in patients suffering from anal canal cancer. Based on the results of sentinel node biopsies, a selective approach could be proposed where node-positive patients could be selected for inguinal node irradiation while node-negative patients could take advantage of inguinal sparing irradiation, thus avoiding toxic side effects.

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology.

Lymphatic mapping and sentinel lymph node biopsy in epidermoid carcinoma of the anal canal

AIM

Although 15-25% of patients with anal cancer present with superficial inguinal lymph node metastases but the routine application of groin irradiation is controversial because of serious side effects. Inguinal sentinel lymph node biopsy (SLNB) can be used to select patients appropriately for inguinal radiation. The study evaluates the efficiency and clinical impact of SLNB.

METHODS

Forty patients with anal cancer underwent 1 ml Tc(99m)-Nanocolloid injection in four sites around the tumour. Patients with inguinal radio colloid enrichment were selected for sentinel lymph node biopsy (SLNB). Lymph node status was examined by haematoxylin and eosin (H&E) as well as immunohistochemistry-staining. All SLN-positive patients were scheduled for inguinal radiation; SLN-negative patients with T1 and early T2 tumours were not scheduled for inguinal radiation.

RESULTS

SLN were detected in 36/40 patients. Three common patterns of lymphatic drainage were observed: mesenterial, iliacal and inguinal. Twenty patients with inguinal SLN underwent SLN-biopsy. 6/20 patients were SLN-positive. In 10/20 patients SLNB altered the therapy plan--four patients with T1-tumours and positive SLN had additional groin irradiation, whereas 6 patients with small T2-tumors and tumour-free inguinal SLN did not undergo inguinal irradiation.

CONCLUSIONS

Inguinal sentinel node biopsy in anal cancer is efficient and could assist in the decision for inguinal radiation. The validity and safety of the proposed therapeutic algorithm has to be proven by a larger, prospective study.

Sentinel lymph node biopsy for gastrointestinal cancers

Sentinel lymph node biopsy (SLNB) in gastrointestinal-(GI)-tract cancer is not yet of clinical relevance. Nevertheless, the results in the upper GI-tract promise to be helpful to individualize the indication for surgical therapy. SLNB in colon cancer still fails to show high validity to predict the nodal status, but may be helpful to clarify the prognostic role of micrometastases/isolated tumor cells. In anal cancer SLNB is able to guide the indication for groin irradiation.

Bilan préthérapeutique initial du carcinome épidermoïde invasif de l’anus

Anal epidermoid carcinoma is a rare malignant tumor, comprising less than 5% of all carcinomas of the colon, rectum, and anus. The primary therapy now includes radiotherapy, often in combination with chemotherapy. Radical surgery is now rarely indicated. Therapeutic indications are based on locoregional staging, the presence of visceral metastases and an evaluation of the medical history. Anorectal endosonography is helpful in evaluating locoregional extension. In addition, magnetic resonance imaging, positron emission tomography scanning and inguinal sentinel lymph node procedure should play a role in a more selective approach in patients with anal carcinoma.

Sentinel Lymph Node Biopsy in Cutaneous Squamous Cell Carcinoma: A Systematic Review of the English Literature

BACKGROUND

Although most cutaneous squamous cell carcinoma (SCC) is curable by a variety of treatment modalities, a small subset of tumors recur, metastasize, and result in death. Although risk factors for metastasis have been described, there are little data available on appropriate workup and staging of patients with high-risk SCC.

OBJECTIVE

We reviewed reported cases and case series of SCC in which sentinel lymph node biopsy (SLNB) was performed to determine whether further research is warranted in developing SLNB as a staging tool for patients with high-risk SCC.

METHODS

The English medical literature was reviewed for reports of SLNB in patients with cutaneous SCC. Data from anogenital and nonanogenital cases were collected and analyzed separately. The percentage of cases with a positive sentinel lymph node (SLN) was calculated. False negative and nondetection rates were tabulated. Rates of local recurrence, nodal and distant metastasis, and disease-specific death were reported.

RESULTS

A total of 607 patients with anogenital SCC and 85 patients with nonanogenital SCC were included in the analysis. A SLN could not be identified in 3% of anogenital and 4% of nonanogenital cases. SLNB was positive in 24% of anogenital and 21% of nonanogenital patients. False-negative rates as determined by completion lymphadenectomy were 4% (8/213) and 5% (1/20), respectively. Most false-negative results were reported in studies from 2000 or earlier in which the combination of radioisotope and blue dye was not used in the SLN localization process. Complications were reported rarely and were limited to hematoma, seroma, cutaneous lymphatic fistula, wound infection, and dehiscence.

CONCLUSIONS

Owing to the lack of controlled studies, it is premature to draw conclusions regarding the utility of SLNB in SCC. The available data, however, suggest that SLNB accurately diagnoses subclinical lymph node metastasis with few false-negative results and low morbidity. Controlled studies are needed to demonstrate whether early detection of subclinical nodal metastasis will lead to improved disease-free or overall survival for patients with high-risk SCC.

Surgical Management of Primary Cutaneous Melanoma: Excision Margins and the Role of Sentinel Lymph Node Examination

Surgical strategies for managing patients who have primary cutaneous melanoma have changed dramatically over the past 30 years. More conservative excision margins have been shown to be adequate, and routine complete lymph node dissection (CLND)has been abandoned since the sentinel node (SN) biopsy technique was introduced. Knowledge of a patient's SN status not only provides a reliable guide to prognosis, but also allows CLND to be avoided in 80% to 85% of patients. Recent clinical trial results suggest that SN biopsy, with immediate CLND if an SN is positive,confers a survival advantage in those who have metastatic disease in regional nodes. Minimally invasive and noninvasive methods of SN assessment, such as magnetic resonance spectroscopy, are being evaluated.

Sentinel node biopsy for cT1 and cT2a gastric cancer

AIMS

To evaluate the feasibility and accuracy of sentinel node (SN) biopsy for gastric cancer.

PATIENTS AND METHODS

One hundred patients with gastric cancer diagnosed as cT1 (n=80) or cT2a (n=20) were enrolled. Indocyanine green-stained SNs were analysed by hematoxylin and eosin staining (n=100) and by cytokeratin immunohistochemistry (n=50).

RESULTS

SNs were identified in 94 of the 100 patients and the mean number of SNs was 4.4 (range, 1-12). Of these 94 patients, 14 patients had lymph node metastases. Two patients with T1 and one patient with T2 had metastases in non-SNs alone by hematoxylin and eosin staining (diagnostic accuracy =97.3% in T1 and 95.0% in T2). All three patients with a false negative result had a tumour, which was more than 4 cm in size and signet ring cell histology. In two of them, the tumour was located at lesser curvature. By immunohistochemical staining, three patients with T1 and one patient with T2 were found to have lymph node micrometastases in non-SNs alone among 45 patients (diagnostic accuracy =92.1% in T1, 85.7% in T2).

CONCLUSION

SN biopsy using indocyanine green can be performed rapidly and easily with a high detection rate and accuracy in patients with T1 gastric cancer. However, it should be performed with caution for large tumours with a signet ring cell histology located at lesser curvature due to the possibility of a false negative result.

Lymphatic mapping in management of patients with primary cutaneous melanoma

In patients with primary cutaneous melanoma, knowledge of regional lymph-node status provides important information on outlook. Evidence suggests that early removal of nodes that contain metastatic disease improves survival outcome. Lymphatic drainage occurs first to sentinel nodes, which are therefore the nodes most likely to contain metastatic disease. Lymphatic mapping with lymphoscintigraphy is important to identify reliably sentinel nodes for removal and thus establish the status of regional nodes. Mapping studies in patients with melanoma have provided new insights into lymphatic anatomy and have shown previously unsuspected drainage pathways, which have important implications for accurate identification and removal of sentinel nodes. Because it is impossible to predict the site or sites of sentinel nodes clinically in individual patients, routine preoperative lymphoscintigraphy is a prerequisite if reliable results are to be obtained from sentinel-node biopsy.

Management of anal canal cancer

PURPOSE

Chemoradiotherapy has replaced radical surgery as the initial treatment of choice for anal canal cancer. The roles of these therapeutic modalities are discussed and recommendations on management of anal canal cancer are made based on currently available evidence. Areas for further studies also are identified.

METHODS

Literature on management of anal canal cancer from January 1970 to July 2003 obtained via MEDLINE was reviewed. Reports on anal margin cancers were excluded.

RESULTS

Randomized, prospective, Phase 3 trials in Europe and the United States showed that chemoradiotherapy with 5-fluorouracil and mitomycin C was superior in local control, colostomy-free rate, progression-free survival, and cancer-specific survival compared with radiation alone. In larger tumors, the addition of mitomycin C to radiotherapy and 5-fluorouracil improves local control, colostomy-free, and disease-free survival but is associated with more acute hematologic toxicity. Chemoradiotherapy, including Cisplatin and 5-fluorouracil, appeared to be equal or superior to surgery as salvage therapy in patients with residual disease six weeks after initial nonsurgical treatment.

CONCLUSIONS

To improve treatment outcomes and reduce treatment-related toxicities, further studies are required to elucidate the optimal drug combination and doses, optimal radiation field, total dose, and fraction sizes. Randomized, multicenter trials are needed to define the treatment protocol that provides the highest rate of sphincter preservation with acceptable toxicity. Few studies addressed the treatment of metastatic disease, which remains a major cause of mortality.

Salvage abdominoperineal resection after failure of conservative treatment in anal epidermoid cancer

PURPOSE

Radiotherapy alone or with combined chemotherapy is the first therapeutic option for epidermoid carcinoma of the anal canal. Failure of this conservative treatment may benefit of salvage abdominoperineal resection. This study was designed to analyze postoperative outcome and oncologic results in a single anticancer institution.

METHODS

Medical charts of 36 patients (median age, 57.9 years) who underwent salvage abdominoperineal resection after failure of conservative treatment between 1987 and 2002 were reviewed retrospectively. There were 15 patients treated for immediate failure (Group I) and 21 patients for recurrence (Group II). Twenty-two patients have undergone primary use of flap reconstruction of the perineal wound. There were ten rectus abdominis myocutaneous flaps, nine omental flaps, two gracilis muscular flaps, and one combined flap.

RESULTS

There was no postoperative mortality. Median follow-up was 67 (range, 15-155) months. Primary closure of the perineum was obtained in 33 patients (92 percent). Secondary wound breakdown occurred in 23 of 33 patients (70 percent). Complications unrelated to the perineal wound occurred in 13 patients. The overall crude five-year survival after salvage abdominoperineal resection was 69.4 percent. The crude five-year survival in Group I and Group II was 60.7 and 71.5 percent respectively (P = 0.28). The crude five-year, disease-free survival in Groups I and II was 31.1 and 48.2 percent respectively (P = 0.10). Twenty-three patients experienced recurrences after salvage abdominoperineal resection (64 percent) with a mean delay of 30 months.

CONCLUSIONS

Despite high incidence of perineal morbidity, salvage abdominoperineal resection for epidermoid carcinomas of the anal canal has a high long-term survival rate.

Sentinel lymph node mapping in colon and rectal cancer: its impact on staging, limitations, and pitfalls

Sentinel lymph node (SLN) mapping has been widely applied in the staging of solid neoplasms including colon and rectal cancer. Since the first reported feasibility study in 1997, there have been numerous publications validating SLN mapping as a highly accurate and powerful upstaging technique for colon and rectal cancer. In addition to refining the technical aspects of this procedure, these studies have investigated the use of other tracers and operative techniques, while determining the indications, limitations, and pitfalls of SLN mapping in patients with colorectal cancers. This chapter reviews the rationale for performing SLN mapping for the accurate staging of colon and rectal cancers, and provides a brief review of the historical background of the development of the procedure. Landmark publications, which have contributed to the current status of the technique, are discussed. We will focus on the technical details of the procedure, and on the pathological evaluation of the specimen and the SLNs. The various tracers and techniques of SLN mapping in colon and rectal cancer will be discussed. We have performed SLN mapping in more than 240 consecutive patients over the past 7 years. The success rates for identifying at least one SLN for colon and rectal cancer were 100% and 90.6%, respectively. The accuracy rates were 95.8% and 100%, respectively. In terms of upstaging, 32.3% of colon cancer patients with nodal metastases and 16.7% of rectal patients with nodal metastases were upstaged by the detection of micrometastases found in the SLNs only. Finally, we will also discuss the current role as well as the future research directions for SLN mapping in colon and rectal cancer.

[Methods of sentinel lymph node mapping]

Sentinel lymph node mapping is used as a diagnostic method in order to increase staging accuracy without the well-known morbidities of radical lymphadenectomy. The sentinel node is defined as the first node to receive lymphatic drainage from a primary tumor. The sentinel node concept postulates that if the first draining node is negative for metastasis, the remaining lymph nodes in the nodal basin can be spared. Thus one can predict the status of the nodal basin with high accuracy. It also shows that lymphatic spread seems to follow certain rules that do not concern the whole lymphatic basin. Skip metastases were proven to be rare in breast and gastric cancer. The main issue in sentinel lymph node mapping remains the improvement of staging accuracy for detection of lymph nodes most likely to develop metastasis as well as reducing morbidity by planning lymphadenectomies individually for each tumor and each patient.

Historical review of lymphatic mapping in gastrointestinal malignancies

The advent of sentinel lymph node mapping (SLNM) has had a profound impact on the surgical management of breast cancer and melanoma over the past decade. However, SLNM in gastrointestinal malignancies is still in its infancy. The role of SLNM in gastrointestinal malignancies is to increase staging accuracy and to reduce the understaging associated with standard surgical and pathological techniques. Numerous authors have described the successful use of SLNM in colon, rectal, gastric, esophageal, and anal canal malignancies, with a high degree of accuracy and upstaging by detailed pathological analysis of the sentinel nodes. Over the past 2 years, research and publications related to gastrointestinal lymphatic mapping have dramatically increased worldwide.

Refined staging by sentinel lymph node biopsy to individualize therapy in anal cancer

We evaluated the feasibility of the sentinel lymph node technique to refine staging and potentially individualize therapy for anal cancer. Seventeen patients with cancer of the anal canal underwent peritumoral injection of 99mTc-colloid, followed 17 hours later by lymphoscintigraphy. A selective lymph node biopsy (SLNB) was attempted in 12 of 13 cases with scintigraphically detected SLNs. Lymph node metastases were present in 5 of 12 cases (42%); in 2 of these 5 cases, micrometastases were detected only by immunohistochemical staining. Hence, SLNB refines the diagnostic workup for anal cancer and provides an accurate basis for individualized therapy.

Inguinal sentinel lymph node biopsy for staging anal cancer

BACKGROUND AND AIMS

The optimal treatment of clinically negative inguinal lymph nodes in patients with primary anal cancer has not yet been clearly defined. The presence of metastases in the inguinal lymph nodes is an adverse prognostic factor for anal cancer. In the present study the feasibility of sentinel lymph node biopsy (SLNB) for staging anal cancer was investigated.

PATIENTS AND METHODS

From September 1999 to March 2002, 8 patients with biopsy proven primary anal cancer underwent lymphoscintigraphy and dual-agent guided inguinal SLNB for nodal staging before starting multimodality treatment.

RESULTS

Inguinal SLNB was successful in all 8 patients (13 groins). A total of 20 hot and blue SLNs (mean 1,5 (1-2) per groins) were removed. In 2 patients (25%) the SLN was positive for metastasis.

CONCLUSIONS

Lymphoscintigraphy followed by dual-agent guided inguinal SLNB is technically feasible for staging patients with primary anal cancer. The detection of metastases in the removed sentinel lymph node(s) may alter the treatment and thus may improve the locoregional control and overall survival of these patients.

Prognostic factors in anal carcinoma

The pathologist's role in the evaluation of patients with anal squamous carcinoma is now largely restricted to establishing the diagnosis on small biopsies. Staging is performed by imaging techniques and grading is uncertain as the biopsy may not be representative of the whole tumour. Histological subtyping is unreliable and has not been proven to be of prognostic significance. A considerable effort resulting in nearly 50 reports on cytogenetic, flow cytometric, immunohistochemical and other investigations has given new insight into pathogenesis but little guidance with regard to the individual prognosis or choice of treatment. It is concluded that future research should concentrate on larger, probably multicentre series using standardised methods and criteria for evaluation.