Impacto del fenómeno de migración de estadio ganglionar en la supervivencia y la recurrencia de pacientes con cáncer papilar de tiroides sometidos a vaciamiento ganglionar profiláctico / Impact of the node-stage migration phenomenon on survival and recurrence of patients with papillary thyroid cancer who underwent prophylactic lymphnode dissection

Introducción. Dado que un ensayo clínico aleatorio es irrealizable, el rol del vaciamiento ganglionar profiláctico en pacientes con cáncer papilar de tiroides sin comprobación clínica de compromiso ganglionar metastásico (cN0) es controversial. El vaciamiento ganglionar profiláctico acarrea un proceso de reclasificación de pacientes, al hacer evidente la positividad ganglionar micrometastásica antes ignorada, lo que genera una aparente pero falsa mejoría en los desenlaces de los grupos de estadificación, mientras el pronóstico individual y total de la población no cambia, fenómeno conocido como migración de estadio o fenómeno de Will Rogers. Métodos. Se ejecutaron simulaciones de poblaciones con cáncer papilar de tiroides con compromiso ganglionar metastásico clínicamente evidente (cN+) y cN0, para determinar el impacto del fenómeno de migración de estadio en los pacientes sometidos a vaciamiento ganglionar profiláctico. Resultados. Con la simulación de las poblaciones y sus estadios ganglionares, se observa cómo la migración de estadio ganglionar genera una aparente mejoría en los desenlaces de recurrencia loco regional y supervivencia, sin cambiar los desenlaces de la población total ni individuales. Discusión. El fenómeno de migración de estadio es uno de los sesgos más importantes que limitan el uso de grupos históricos de control en ensayos de tratamiento experimental. De acuerdo con nuestros resultados, este fenómeno podría explicar los beneficios observados con el vaciamiento ganglionar profiláctico en algunos de los estudios agregativos publicados hasta el momento, hallazgos que no han sido documentados para el cáncer papilar de tiroides

Introduction. The role of prophylactic central lymph node dissection at the time of total thyroidectomy remains controversial in clinically node-negative (cN0) papillary thyroid carcinoma. Moreover, a prospective randomized controlled trial of prophylactic central lymph node dissection in cN0 RCT is not readily feasible. Methods. In this study we simulated cN0 and clinically node-positive (cN+) populations, to evaluate impact of nodal stage migration in papillary thyroid carcinoma patients that undergo prophylactic central neck dissection. We use simulations of population and nodal stages .Results. Nodal stage migration phenomenon seems to have an improvement in locoregional recurrence and overall survival of cN0 and cN+ populations, without changes in overall population and individual outcomes.Discussion. Nodal stage migration is recognized as an important bias that precludes the use of historical controls groups in experimental treatment trials. In accordance to our findings, this phenomenon could explain the improvements observed in outcomes in patients that undergo prophylactic central neck dissection

The impact of lymph node count on survival in gastric cancer

PURPOSE: The purpose of this study was to determine the immunologic role of lymph node (LN) and stage migration by assessing LN count and metastatic LN count.METHODS: A total of 2,117 patients with gastric adenocarcinoma located in the body and antrum who underwent distal/subtotal gastrectomy with D2 LN dissection between January 1, 1998 and December 31, 2008 were enrolled. LN count and number of metastases were determined in the N1 tier (area of D1 dissection) and N2 tier (area of D2 dissection). The lower and upper quartiles of LN counts in the same pN stage were grouped to compare the prognosis and LN positivity according to the LN tier.RESULTS: Stage migration from N1 tier to N2 tier occurred in 3.2% of cases. The 5-year disease-specific survival rates of the upper and lower LN count groups within the N1 tier were 91.0% and 86.7% (P=0.01), respectively. LN positivity in the N2 tier of the lower LN count group was higher than that of the upper LN count group (14.1% vs. 8.2%, P < 0.01). Stage migration in the N2 tier of the lower LN count group was also higher than that of the upper LN count group (4.6% vs. 1.8%, P < 0.01).CONCLUSION: The lower LN count group had a decreased survival rate compared to that of the upper LN count group, suggesting that perigastric LN has an immunological defense role in weakening the disseminating power of metastatic tumor cells, as indicated by the LN count.

A Comparison of Outcomes for the Patients with Pathologically Node-negative Breast Cancer and Who Were Treated Either with Sentinel Lymph Node Biopsy Only or with Conventional Axillary Lymph Node Dissection / 한국유방암학회지

PURPOSE: False negative results obtained with the use of a sentinel lymph node biopsy (SLNB) can result in down staging of tumors, whereas the use of a more elaborated pathological examination of sentinel lymph nodes might lead to upstaging of tumors. The purpose of this study was to compare results after performing only an SLNB as compared with performing conventional axillary lymph node dissection (ALND) without an SLNB in pathologically node negative (pN0) breast cancer patients. METHODS: From April 2004 to June 2007, SLNBs were performed for patients with primary breast cancer who had no clinical evidence of a lymph node metastasis. A total of 272 patients were treated with only an SLNB. During the same period, 278 patients were confirmed as pN0 after conventional ALND without an SLNB. A prospectively collected database and medical records of these patients were reviewed. RESULTS: For patients that had undergone only an SLNB, there was no local or regional recurrence. A distant metastasis developed in four patients (1.5%). In patients that had undergone ALND without an SLNB, a recurrence was found in 13 patients (4.7%). Patients that had undergone only an SLNB showed significantly better disease-free survival as compared to patients that had undergone ALND without an SLNB (p=0.032). CONCLUSION: pN0 patients treated with only an SLNB showed a significantly better outcome as compared to patients treated with conventional ALND without an SLNB. These results suggest that performing an SLNB might result in the upstaging of a subset of patients who would have been understaged by the use of conventional ALND.

Stage Migration of Gastric Cancer According to the Extent of Lymph Node Dissection

PURPOSE: In this study, the authors attempted to evaluate the stage migration phenomenon according to D1 lymphadectomy and D2 lymphadectomy in the same patients. METHODS: A retrospective study was performed in 300 consecutive patients with gastric cancer who had undergone curative resection with nodal yields of D2 or more from 1994 to 1997. The lymph node status was evaluated in two different extents. Group B included patients with whole harvested regional lymph nodes (D2<) while group A include patients with perigastric lymph nodes (D1). Each group was staged by the number of involved lymph nodes according to the UICC-TNM stage (5th), and by the ratio of involved to resected lymph nodes. Stage migration and the difference of 5YSR were observed between the two groups. RESULTS: In staging by the number of involved lymph nodes, 25 cases (8.3%) of group B were staged up. According to the status by the ratio of involved lymph nodes, 14 cases (4.6%) of group B were staged up and 28 (9.3%) were staged down. CONCLUSION: In the staging of gastric cancer, adequate lymph node dissection was essential for accurate lymph node staging. In the cases of limited lymph node dissection, some extent of stage migration was considered assessing in the prognosis.