Colonic stent vs surgical resection of the primary tumor. Effect on survival from stage-IV obstructive colorectal cancer

BACKGROUND AND OBJECTIVES

the impact of surgical primary tumor resection on survival of obstructive metastatic colorectal cancer remains controversial. The primary goal of this study was to analyze survival in patients with obstructive metastatic colorectal cancer after treatment with either resection surgery or a colonic stent.

MATERIAL AND METHODS

a prospective study was performed of all patients with stage-IV colorectal cancer and obstructive manifestations, diagnosed from 2005 to 2012 and managed with either resection surgery or a colonic stent. Cases with a perforation, abscess, right colon or distal rectal malignancy, multiple colorectal cancer or derivative surgery were excluded.

RESULTS

a total of 95 patients were included, 49 were managed with resection surgery and 46 with a colonic stent. The colonic stent group had a higher Charlson index (9.5 ± 2.1 vs 8.6 ± 1.5, p = 0.01), a shorter time to oral intake (0.9 ± 1.1 vs 16.4 ± 53.5 days, p = 0.05), a shorter hospital stay (4 ± 4.8 vs 16.7 ± 15.5 days, p = 0.0001), less need for stomata (11.1 % vs 32.7 %, p = 0.01), fewer early complications (4.3 % vs 46.9 %, p = 0.0001) and more late complications (33.3 % vs 6.4 %, p = 0.001). Undergoing chemotherapy (p = 0.008) was the only independent factor related to increased survival. In the subgroup of patients managed with chemotherapy, surgical primary tumor resection was an independent factor associated with increased survival.

CONCLUSION

both treatments are effective for resolving obstructive manifestations in patients diagnosed with stage-IV obstructive colorectal cancer. Resection surgery has no positive impact on survival and thus cannot be recommended as a therapy of choice.

Sudden Death of Citrus in Brazil: A Graft-Transmissible Bud Union Disease

Citrus Sudden Death (CSD), a new, graft-transmissible disease of sweet orange and mandarin trees grafted on Rangpur lime rootstock, was first seen in 1999 in Brazil, where it is present in the southern Triângulo Mineiro and northwestern São Paulo State. The disease is a serious threat to the citrus industry, as 85% of 200 million sweet orange trees in the State of São Paulo are grafted on Rangpur lime. After showing general decline symptoms, affected trees suddenly collapse and die, in a manner similar to trees grafted on sour orange rootstock when affected by tristeza decline caused by infection with Citrus tristeza virus (CTV). In tristeza-affected trees, the sour orange bark near the bud union undergoes profound anatomical changes. Light and electron microscopic studies showed very similar changes in the Rangpur lime bark below the bud union of CSD-affected trees: size reduction of phloem cells, collapse and necrosis of sieve tubes, overproduction and degradation of phloem, accumulation of nonfunctioning phloem (NFP), and invasion of the cortex by old NFP. In both diseases, the sweet orange bark near the bud union was also affected by necrosis of sieve tubes, and the phloem parenchyma contained characteristic "chromatic" cells. In CSD-affected trees, these cells were seen not only in the sweet orange phloem, but also in the Rangpur lime phloem. Recent observations indicated that CSD affected not only citrus trees grafted on Rangpur lime but also those on Volkamer lemon, with anatomical symptoms similar to those seen in Rangpur lime bark. Trees on alternative rootstocks, such as Cleopatra mandarin and Swingle citrumelo, showed no symptoms of CSD. CSD-affected trees did recover when they were inarched with seedlings of these rootstocks, but not when inarched with Rangpur lime seedlings. These results indicate that CSD is a bud union disease. In addition, the bark of inarched Rangpur lime and Volkamer lemon seedlings showed, near the approach-graft union, the same anatomical alterations as the bud union bark from the Rangpur lime rootstock in CSD-affected trees. The dsRNA patterns from CSD-affected trees and unaffected trees were similar and indicative of CTV. CSD-affected trees did not react by immunoprinting-ELISA using monoclonal antibodies against 11 viruses. No evidence supported the involvement of viroids in CSD. The potential involvement of CTV and other viruses in CSD is discussed.

Incidence and epidemiology of Citrus tristeza virus in the Valencian community of Spain

The first outbreak of citrus tristeza disease in Spain caused by Citrus tristeza virus (CTV) was recorded in 1957 in the Valencian Community (VC). In total c. 40 million trees, mainly of sweet orange and mandarin grafted on sour orange rootstocks, declined due to CTV. Large-scale surveys in different municipalities of the VC indicated that the disease spread very fast. Incidence increased from 11% in 1989 to 53% in 1998. Toxoptera aurantii and Aphis spiraecola (inefficient aphid vectors of CTV) predominated before 1985-87. Since then the relatively efficient vector Aphis gossypii has become dominant and induced an epidemic that has been modelled. The large number of A.gossypii that visited each clementine tree (estimated to exceed 97000 per year) explained the difference between the temporal pattern of spread of CTV in clementine which followed the Gompertz model and that in sweet orange (logistic model). The susceptibility of the different citrus species to CTV infection by aphids seems to depend on the number of young, succulent shoots produced. The epidemiological data allowed specific recommendations to be made to growers in order to facilitate a change to a modern citrus industry based on the use of selected varieties grafted on tristeza-tolerant rootstocks produced within a certification scheme. This has been done already in almost 90% of the VC citrus-growing area. The tristeza problem has been solved unless more aggressive isolates are introduced and become prevalent.