Is total mesorectal excision always necessary for T1-T2 lower rectal cancer?
ABSTRACT The goal of this multicenter study was to clarify the determinants of local excision for patients with T1-T2 lower rectal cancer.
Data from 567 consecutive patients who underwent radical resection for T1-T2 lower rectal cancer at 12 institutions between 1991 and 1998 were reviewed. Rates of lymph node metastasis were investigated using a tree analysis, which was hierarchized using independent risk factors for nodal involvement.
The independent risk factors for lymph node metastasis were female gender, depth of tumor invasion, histology other than well-differentiated adenocarcinoma, and lymphatic invasion. According to the first three parameters that can be obtained preoperatively, only 0.99% of the patients without risk factors had lymph node metastasis. On the other hand, even if the lower rectal cancer was at stage T1, women with histological types other than well-differentiated adenocarcinoma had an approximately 30% probability of having lymph node metastasis. Lymphatic invasion was most useful to predict nodal involvement among patients with T2 lower rectal cancer. The rates of lymph node metastasis in T2 patients with and without lymphatic invasion were 32.9% and 9.1%, respectively.
Gender is one of the most important predictors for lymph node metastasis in patients with early distal rectal cancer. Three parameters, including depth of tumor invasion, histology, and gender, are useful determinants for local excision. Additional studies are required to establish the minimum optimal treatment for T2 lower rectal cancer.
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ABSTRACT: Background The accurate preoperative diagnosis of depth of tumor invasion and nodal status in distal rectal cancer is important because neoadjuvant chemotherapy or lateral pelvic lymph node dissection is indicated for patients with T3–T4 tumor or nodal involvement. This study aimed to determine the optimal cutoff value for predicting lymph node metastasis in patients with distal rectal cancer using multidetector row computed tomography (MDCT). Methods The study investigated 77 patients who had undergone surgery for distal rectal cancer at a single institution between 2008 and 2011. Diagnostic performance for depth of tumor invasion and mesorectal and lateral pelvic lymph node metastases was evaluated. The optimal cutoff value was determined by receiver operating characteristic curve analysis. Results For predicting mesorectal and lateral pelvic lymph node metastasis, MDCT had a sensitivity of 0.36 and 0.89 and a specificity of 0.78 and 0.97, respectively. The optimal cutoff values of major and minor axes lengths for predicting mesorectal lymph node metastasis were 6.5 mm and 5.7 mm, respectively. The areas under the curve (AUCs) were 0.82 and 0.88, respectively. For predicting lateral lymph node metastasis, the optimal cutoff values were 9 mm for the major axis and 6 mm for the minor axis. Both AUCs were 1. Conclusions Using MDCT, the optimal cutoff value of minor axis length for predicting mesorectal and lateral pelvic lymph node metastases in patients with distal rectal cancer was 6 mm. The accuracy of MDCT was satisfactory for predicting lateral pelvic lymph node metastasis.Annals of Surgical Oncology 08/2014; 22(1). DOI:10.1245/s10434-014-3972-3 · 3.94 Impact Factor
Conference Paper: A 2.2 V 300 /spl mu/A RDS pager baseband decoder[Show abstract] [Hide abstract]
ABSTRACT: Compared with more advanced wireless telecommunication systems such as GSM, the pager offers the advantages of a lower cost, a smaller size and a longer battery autonomy. Furthermore, the RDS pager system allows reuse of the existing network of FM radio broadcasting stations, reducing the cost of introduction of the pager network and allowing immediately a large geographical coverage. The realization ofthe RDS baseband decoder described is a first step of an attempt to increase the pager battery autonomy from a few weeks to more than a half year.Solid-State Circuits Conference, 1997. Digest of Technical Papers. 43rd ISSCC., 1997 IEEE International; 01/1997
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ABSTRACT: T1 rectal cancer can be treated using various strategies. Endoscopic or transanal resection is the first choice of treatment when tumors are not associated with risk for lymph node metastasis. However, transabdominal resection with lymphadenectomy is recommended for tumors that do confer risk of lymph node metastasis. The prognosis after transabdominal resection is satisfactory, but various dysfunctions impair the postoperative quality of life. The standard treatment for T3–T4 rectal cancer is total mesorectal excision with preoperative chemoradiotherapy in Western countries and total mesorectal excision with laterallymph node dissection in Japan. Previous reports indicate that preoperative radiotherapy contributes to a lower rate of local recurrence, although overall survival is not affected. In addition, radiotherapy increases the prevalence of sexual dysfunction and fecal incontinence. The effect of perioperative chemoradiotherapy for T1–T2 rectal cancer remains unclear.Digestive Endoscopy 05/2013; 25(S2). DOI:10.1111/den.12068 · 1.99 Impact Factor