Magnetic resonance imaging (MRI)-based indication for neoadjuvant treatment of rectal carcinoma and the surrogate endpoint CRM status.

AIM: Is it possible to reduce the frequency of neoadjuvant therapy for rectal carcinoma and nevertheless achieve a rate of more than 90% circumferential resection margin (CRM)-negative resection specimens by a novel concept of magnetic resonance imaging (MRI)-based therapy planning? MATERIALS AND METHODS: One hundred eighty-one patients from Berlin and Mainz, Germany, with primary rectal carcinoma, without distant metastasis, underwent radical surgery with curative intention. Surgical procedures applied were anterior resection with total mesorectal excision (TME) or partial mesorectal excision (PME; PME for tumours of the upper rectum) or abdominoperineal excision with TME. RESULTS: With MRI selection of the highest-risk cases, neoadjuvant therapy was given to only 62 of 181 (34.3%). The rate of CRM-negative resection specimens on histology was 170 of 181 (93.9%) for all patients, and in Berlin, only 1 of 93 (1%) specimens was CRM-positive. Patients selected for primary surgery had CRM-negative specimens on histology in 114 of 119 (95.8%). Those selected for neoadjuvant therapy had a lower rate of clear margin: 56 of 62 (90%). CONCLUSION: By applying a MRI-based indication, the frequency of neoadjuvant treatment with its acute and late adverse effects can be reduced to 30-35% without reduction of pathologically CRM-negative resection specimens and, thus, without the danger of worsening the oncological long-term results. This concept should be confirmed in prospective multicentre observation studies with quality assurance of MRI, surgery and pathology.

Complement components and terminal complement complex in oesophageal smooth muscle of patients with achalasia.

This study investigates whether patients with achalasia exhibit autoimmune reactions with subsequent complement activation within oesophageal smooth muscle, vessels and neurones. Oesophageal muscular biopsies from 8 patients undergoing surgery for achalasia and from 6 patients operated for oesophageal cancer were investigated by immunofluorescence for the presence of the complement components C1q, C4, C3c, C3d, C9 and the C9 neoantigen of the terminal C5b-C9 complement complex. Tissues were also investigated for the expression of immunoglobulins (G,A,M) and of the antigens of rubella and varicella zoster viruses. In addition, sera of both patient groups were tested for the presence of autoantibodies against Auerbach's plexus. The terminal complement complex C5b-C9 was found within muscle cells from all patients with achalasia but in only one specimen from a patient with cancer. Two patients with achalasia also exhibited the terminal complement complex as well as IgM within ganglion cells. Muscle cells stained positive for the complement component C9 in all five patients with achalasia in whom this test was performed but in none of the control tissues. In addition, sera from four patients with achalasia contained antibodies against Auerbach's plexus. Studies for the complement components C1q, C4, C3c and for antigens of rubella and varicella zoster viruses revealed negative results in all patients and controls. The results of this study suggest that a complement activation is involved in the autoimmune pathogenesis of achalasia. However, the triggering mechanism of this phenomenon remains to be determined.

How many lymph nodes are needed for an accurate pN classification in esophageal cancer? Evidence for a new threshold value.

BACKGROUND/AIMS: The UICC recommends a number of at least six lymph nodes to be examined in the surgical therapy of esophageal cancer for a reliable pN classification. The aim of this study was to evaluate this threshold by means of the data from our patients. METHODOLOGY: Following curative resection (R0) of esophageal cancer the numbers of examined tumor-free and tumor-involved lymph nodes were compared. Different statistical models of logistic regression were fitted to the data and checked for plausibility (Hosmer Lemeshow test). The sensitivity of a correct pN classification was then calculated and correlated to the total number of examined lymph nodes. RESULTS: A maximum increase of the sensitivity in classifying pN occurred from 0 to 6 examined lymph nodes. Nevertheless an additional improvement of sensitivity was continuously shown up to 100 examined nodes. An over 90% sensitivity of a correct lymph node classification was reached when more than twelve nodes were examined. Thus the results demonstrate in the case of esophageal cancer, that the suggestion by the UICC to examine at least 6 nodes for defining pN appears too low and may not represent the clinical situation. A ninety percent confidence level of a correct lymph node classification can be expected above 12 examined nodes similarly to the current recommended threshold in colorectal carcinoma. CONCLUSIONS: We suggest a new threshold for the number of examined lymph nodes of at least 12 instead of 6 nodes for accurately defining the pN category in esophageal cancer.