Should all patients with duodenal adenocarcinoma be considered for aggressive surgical resection?

BACKGROUND: Long-term survival for duodenal adenocarcinoma is inconsistent in the literature, and the biology of duodenal adenocarcinoma is poorly understood. METHODS: One institution's experience with duodenal adenocarcinoma from 1984 to 2005 is reviewed. Clinicopathologic data were analyzed, and overall survival was estimated using Kaplan-Meier curves with log-rank test. RESULTS: Of the 52 patients, 35 (67%) underwent potentially curative surgery; 31 survived the postoperative period and were included in the analysis. Of these, the median survival was 34 months (range 6 to 186 months) compared with 13 months (range 1 to 24 months) for those not undergoing curative surgery (P < or = .001). Clinicopathologic factors favoring long-term survival were tumor size >3.5 cm (P < or = .001) and T-stage < or =4 (P = .014). CONCLUSIONS: Clinicopathologic factors important to survival in duodenal cancer are T4 tumor status and tumor size. Interestingly, larger tumors were less likely to be invasive, and patients with these tumors had improved survival. The biology of this cancer is poorly understood; therefore, aggressive resection for all duodenal adenocarcinomas is recommended for all patients medically fit to undergo resection.

Studies of the erythrocyte spectrin tetramerization region.

Human erythrocyte spectrin dimers associate at the N-terminal region of alpha spectrin (alpha N) and the C-terminal region of beta-spectrin (beta C) to form tetramers. We have prepared model peptides to study the tetramerization region. Based on phasing information obtained from enzyme digests, we prepared spectrin fragments consisting of the first 156 amino-acid residues and the first 368 amino-acid residues of alpha-spectrin (Sp alpha 1-156 and Sp alpha 1-368, respectively), and found that both peptides associate with a beta-spectrin model peptide, with an affinity similar to that found in alpha beta dimer tetramerization. Spin label EPR studies show that the region consisting of residues 21-46 in alpha-spectrin is helical even in the absence of its beta-partner. Multi-dimensional nuclear magnetic resonance studies of samples with and without a spin label attached to residue 154 show that Sp alpha 1-156 consists of four helices, with the first helix unassociated with the remaining three helices, which bundle to form a triple helical coiled coil bundle. A comparison of the structures of erythrocyte spectrin with other published structures of Drosophila and chicken brain spectrin is discussed. Circular dichroism studies show that the lone helix in Sp alpha-156 associates with helices in the beta peptide to form a coiled coil bundle. Based on NMR and CD results, we suggest that the helices in Sp alpha 1-156 exhibit a looser (frayed) conformation, and that the helices convert to a tighter conformation upon association with its beta-partner. This suggestion does not rule out possible conversion of a non-structured conformation to a structured conformation in various parts of the molecule upon association. Spectrin mutations at residues 28 and 45 of alpha-spectrin have been found in patients with hereditary elliptocytosis. NMR studies were also carried out on Sp alpha 1-156R28S, Sp alpha 1-156R45S and Sp alpha 1-156R45T. A comparison of the structures of Sp alpha 1-156 and Sp alpha 1-156R28S, Sp alpha 1-156R45S and Sp alpha 1-156R45T is discussed.