28.9.11

The Role of Inflammation in Cancer


Highlights
  • Precancerous inflammation can cause increased genetic and epigenetic damage
  • Aberrant oncogenic signaling can induce inflammation
  • The inflammatory response in cancer tissues elicits tumor tissue remodeling and metastases

Brief summary:


Cancer related inflammation can fall into one of two categories: 1. precancerous inflammation lesions and 2. Inflammation that is present in almost all cancer tissues including those that have no precancerous inflammation lesions. The connection between inflammation and cancer can be thought of as consisting of two pathways: an extrinsic mechanism, where a constant inflammatory state contributes to increased cancer risk (such as inflammatory bowel disease); and an intrinsic mechanism, where acquired genetic alterations (such as activation of oncogenes) trigger tumor development (Fig. 1).



The former can increase the risk to cancer development, while the latter are necessary to maintain and promote cancer progression. The roles and the relationship between the two pathways in the cancer development process depend on their specific interactions between genetic/epigenetic factors and environmental factors. The accumulated evidence, obtained using in vivo and in vitro genetic disease models and the analysis of clinical patient samples by various methods including PCR analysis, strongly favors the theory that both precancerous inflammation and inflammation stemming from genetic alteration can cause cell transformation and promote tumor progression. There is strong evidence that inflammation contributes to the incidence of and mortality resulting from a number of tumor types. Examining this relationship via real-time PCR analysis of gene expression and epigenetic state in the inflammatory and tumor microenvironment will contribute to our understanding of cancer initiation and progression and will aid in the discovery of biomarkers for clinical use and drug development (1-3).


1 comment:

mensajes claro said...

Someday cancer will be conquer.

List of all the posts

Interesting Case

Clinical History:

53 years male,History of hypertension and tachycardia,MRI abdomen:-Left adrenal mass:- size 5.8 cm Right renal mass:- size-3.0cm Microscopic examination of the renal mass showed vascular tumor with diffuse sheets of clear cells having Fuhrman grade III nuclei. There was no evidence of necrosis within the tumor. There was no evidence of extraparenchymal invasion.
Gross examination of the left adrenal gland revealed cortically centered, solid and multinodular mass measuring 6.5 x 6.0 x 5.0 cm and weighing 122 grams. The tumor was encapsulated but showed evidence of extraparenchymal penetration. The tumor had golden brown cut surface with areas of hemorrhage and necrosis. The partial nephrectomy showed 3.0cm x 3.0cm x 3.0 cm yellow solid mass which did not invade into the perinephric adipose tissue.
Microscopically, the adrenal mass had predominant diffuse sheets and focal trabecular arrangements. The former pattern was present in about third of tumor. The cells had clear cytoplasm and round to ovoid nuclei with conspicuous nucleoli. Mitotic rate was 9/50 HPF and included atypical forms. Gross necrosis and capsular invasion were documented microscopically. There was no evidence of lymphovascular invasion. Considering the above mentioned features, a Weiss histopathologic score2 of 7/9 was applied.



Discussion:

The differential diagnosis included Renal Cell Carcinoma (RCC) with contralateral adrenal metastasis, Adrenocortical carcinoma (ACC) with contralateral renal metastasis, synchronous RCC and ACC or synchronous RCC and adrenocortical adenoma. A panel of immunohistochemical stains was performed to sort out the diagnosis. Adrenal tumor demonstrated strong Vimentin positivity and is negative for CK7, CK20, E1/AE3, EMA, Synaptophysin and S100.Renal cell carcinoma was positive for CK7, AE1/AE3, EMA (weak) and Vimentin. It was negative for CK20, Synaptophysin and S100. The difference of immunoprofile between the two tumors documented that they originated from two different primaries.

Final Diagnosis:

The diagnosis of synchronous RCC and ACC rather than metastasis influences the prognosis.

Prognosis:

The longest disease free interval after removal of contralateral adrenal metastasis was 12.1 years8 and the longest crude survival was 14.3 years. In contrast non metastazing RCC has an excellent prognosis if no metastasis developed.