PurposeWhen performing a laparoscopic assisted gastrectomy, a function-preserving gastrectomy is performed depending on the location of the primary gastric cancer. This study examined the incidence of lymph node metastasis by the lymph node station number by tumor location to determine the optimal extent of the lymph node dissection.Materials and MethodsThe subjects consisted of 1,510 patients diagnosed with gastric cancer who underwent a gastrectomy between 1996 and 2005. The patients were divided into three groups: upper, middle and lower third, depending on the location of the primary tumor. The lymph node metastasis patterns were analyzed in the total and early gastric cancer patients.ResultsIn all patients, lymph node station numbers 1, 2, 3, 7, 10 and 11 metastases were dominant in the cancer originating in the upper third, whereas station numbers 4, 5, 6 and 8 were dominant in the lower third. In early gastric cancer patients, the station number of lymph nodes with a metastasis did not show a significant difference in stage pT1a disease. On the other hand, a metastasis in lymph node station number 6 was dominant in stage pT1b disease that originated in the lower third of the stomach.ConclusionsWhen performing a laparoscopic-assisted gastrectomy for early gastric cancer, a limited lymphadenectomy is considered adequate during a function-preserving gastrectomy in mucosal (T1a) cancer. On the other hand, for submucosal (T1b) cancer, a number 6 node dissection should be performed when performing a pylorus preserving gastrectomy.

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On January 13, 2016, the largest jackpot prize in world history took place.  In this paper, we examied the Powerball's regressivity from the 16th drawing with a jackpot prize of $301.8 million to the 20th drawing with a jackpot prize of $1.5 billion.  These last five drawings allowed us to examine whether the regressivity continues to decline and turns progressive as jackpot levels approach the billion-dollar mark.  Our sample include Powerball sales from 44 states and the District of Columbia.  Since the cost of living varied across states/jurisdictions, we used real lottery and income data to estimate income elasticity.  For the 16th through 18th drawings, there is a positive relationship between jackpot level and income elasticity.  However, on the 19th drawing with a jackpot of $949.8 million, the income elasticity declined to 0.554 from 0.900.  On the 20th drawing, the income elasticity increased to 0.649 but remained below 0.900 reached on the 18th drawing.