Recurrence risk

Lacunar stroke is characterized by occlusion of a small penetrating artery creating a small deep infarct. Lacunar strokes have the lowest early recurrence risk and best survival rates, but may still cause significant functional morbidity. Although subgroup analyses are available from secondary prevention trials in lacunar stroke, few clinical trial data are available regarding nonthrombolytic antithrombotic therapy for lacunar stroke in the acute setting. 

TABLE 89-4. Initial Management of Prostate Cancer with Low and Intermediate Recurrence Risk... 

Recurrence Risk Expected Survival Initial Therapy... 

Recurrence risk analysis based on pedigree alone ... 

Most commonly, a homozygote is produced by the union of two heterozygous (carrier) parents. The recurrence risk for offspring of such matings is 25% (Fig II-1-4). Occasionally, an affected homozygote mates with a heterozygote in this case the recurrence risk for the offrpring is 50%,... 

Figure 11-1-4. Recurrence Risk for the Mating of Two Heterozygous Carriers (Aa) of a Recessive Mutation...

Figure II-1-7 shows the recurrence risks for X-linked recessive disease.

Figure 11-1-7. Recurrence Risks for X-Linked Recessive Diseases...

I Recurrence risks can be predicted by drawing Punnett squares, j Principles that can characterize single gene diseases j Variable expression in severity of symptoms... 

Recurrence risks for multifactorial disorders increase if the affected individual has a more severe expression of the disease. Again, this reflects the fact that the individual and his or her relatives are located higher on the liability distribution. 

For multifactorial diseases, the recurrence risk decreases rapidly for more remotely related relatives. For example, one study of autism reported a sibling risk of 4.5%, an uncle-niece risk of 0.1%, and a first-cousin risk of 0.05%. In contrast, the risk of carrying a single-gene mutation decreases by only 1/2 with each successive degree of relationship (i.e., 50% chance for siblings, 25% for unde-niece relationships, and 12.5% for first cousins). 

Type 1 diabetes affects approximately 1 in 200 Americans, with a sibling recurrence risk of about 6%. It is an example of an autoimmune disease (see Immunology Lecture Notes), in which self-reactive T cells infiltrate the pancreas to destroy insulin-produdng islet cells. Mutations in the class II major histocompatibility locus (MHC) region are estimated to contribute about one third of the risk of developing type 1 diabetes. Mutations in or near the insulin gene itself are responsible for another 10-15% of the risk. 

Recurrence risks for multifactorial diseases are estimated empirically. 

In general, the evidence suggests that patients who have a recurrence risk of more than 20-30% after radiation therapy alone are likely to benefit from concurrent chemotherapy if they have no major medical contraindications to chemoradiation. 

Lash T et al (2010) Breast cancer recurrence risk related to concurrent use of SSRI antidepressants and tamoxifen. Acta Oncol 49(3) 305-312... 

Baldessarini RJ, Tondo L. Recurrence risk in bipolar manic-depressive disorders after discontinuing lithium maintenance treatment an overview. Chn Drug Invest 1998 15 337-51. 

Davis JP, Chesney PJ, Wand PJ, LaVenture M. Toxic-shock syndrome epidemiologic features, recurrence, risk factors, and prevention. N Engl J Med 1980 303(25) 1429-35. 

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