Immunohistochemical profile for unknown primary adenocarcinoma

Background

Development of tailored treatment based on immunohistochemical profiles (IPs) of tumors for cancers of unknown primary is needed.

Methodology/Principal Findings

We developed an algorithm based on primary known adenocarcinoma for testing sensitivity and specificity. Formalin-fixed paraffin-embedded tissue samples from 71 patients of unfavorable subsets of unknown primary adenocarcinoma were obtained. We examined 15 molecular markers using the algorithm incorporating these IPs and classified the tumours into 9 subsets based on the primary tumour site. The sensitivity and specificity of this algorithm were 80.3% and 97.6%, respectively. Apparent primary sites were lung in 17 patients, digestive organs in 13, gynecological organs in 9, prostate in 7, liver or kidney in 6, breast in 4, urothelial organ in 2, biliary tract and pancreatic profile in none, and unclassified in 13. The response rate to chemotherapy was highest for the gynecological IPs. Patients with gynecological or lung cancer IPs had longer median progression-free survival than those with others: 11.2 months for gynecological IPs (p<0.001) and 6.8 months for lung IPs (p = 0.05). Lung, digestive, prostate, and gynecological profiles were associated with significantly longer median survival time than the other profiles. Multivariate analysis confirmed that the IPs were independent prognostic factors for survival.

Conclusions/Significance

The IPs identified in this study can be used to further stratify patient prognosis for unfavorable subsets of unknown primary adenocarcinoma.     

Chasing the elusive mammalian microautophagy

Different mechanisms for delivery of intracellular components (proteins and organelles) to lysosomes and late endosomes for degradation co-exist in almost all cells and set the basis for distinct autophagic pathways. Cargo can be sequestered inside double-membrane vesicles (or autophagosomes) and reach the lysosomal compartment upon fusion of these vesicles to lysosomes through macroautophagy. In a different type of autophagy, known as chaperone-mediated autophagy (CMA), single individual soluble proteins can be targeted one by one to the lysosomal membrane and translocated into the lumen for degradation. Direct sequestration of proteins and organelles by invaginations at the lysosomal membrane that pinch off into the lumen has also been proposed. This process, known as microautophagy, remains poorly understood in mammalian cells. In our recent work, we demonstrate the occurrence of both "in bulk" and "selective" internalization of cytosolic components in late endosomes and identify some of the molecular players of this process that we have named endosomalmicroautophagy (e-MI) due to its resemblance to microautophagy.     

Chasing coccidia--new tools enter the race

The 8th International Coccidiosis Conference, held on 9--13 July 2001 in Palm Cove, Australia, was a showcase of the latest studies on widely known coccidia, including Eimeria and Toxoplasma in addition to the emerging or re-emerging parasites such as Neospora, Cryptosporidium and Cyclospora. This meeting was staged in conjunction with the Annual Scientific Meeting of the Australian Society for Parasitology.     

The currently declining incidence of cancer of unknown primary

Cancer of unknown primary (CUP) is a heterogeneous group of metastatic cancers for which a primary tumor cannot be identified after a standardized work-up. The biology of CUP has not been fully elucidated and epidemiologic data may be helpful in this regard. The variations in the incidence-rate over time and between countries reflect changes in the risk factors for CUP, incidence trends of the primary tumors that potentially contribute to the burden of CUP and changes in the diagnostic technologies and practice. CUP accounted for 3–5% of cancers in the historical series but its incidence seems to decline in the recent publications. This paper reviews the published cancer-registry studies in order to identify and understand the variations in the incidence-rates of CUP.     

Cost-effectiveness in the diagnosis and treatment of carcinoma of unknown primary origin

Between 2% and 9% of patients with cancer present with metastatic nonsquamous cell carcinoma of unknown primary origin. Traditionally, a series of investigations is undertaken to locate the primary origin of the tumour, although many of these tests are often painful or distressing to patients, unsuccessful in locating the primary site and costly to the health care system. Moreover, even if a tumour is found it usually cannot be treated surgically. However, a small number of cancers of unknown primary origin can be cured, arrested or effectively palliated with systemic treatment. This study compares the costs and outcomes of the current practice of comprehensively searching for the primary tumour with those of an alternative, limited approach that identifies only the primary tumours for which relatively effective systemic therapy exists. Decision trees were constructed for the two diagnostic approaches and their associated therapeutic options. Costs and probabilities were integrated with published data on the survival of patients with each type of cancer. The results indicate that the comprehensive diagnostic strategy may increase 1-year survival rates from 11.0% to 11.5%. On the basis of Ontario cost data it is calculated that the additional costs of a comprehensive search for 1000 patients will range from approximately $2 million to $8 million, depending on the subsequent treatment strategy.     

Chasing the dream: plant EST microarrays

DNA microarray technology is poised to make an important contribution to the field of plant biology. Stimulated by recent funding programs, expressed sequence tag sequencing and microarray production either has begun or is being contemplated for most economically important plant species. Although the DNA microarray technology is still being refined, the basic methods are well established. The real challenges lie in data analysis and data management. To fully realize the value of this technology, centralized databases that are capable of storing microarray expression data and managing information from a variety of sources will be needed. These information resources are under development and will help usher in a new era in plant functional genomics.