Researchers from the M.D. Anderson Cancer Center in Houston conducted an analysis of myelodysplastic syndromes (MDS) patients to determine the general prognoses of MDS patients with chromosome 5 abnormalities. The results showed patients with deletion 5q and monosomy 5 had significantly different survival times.

Chromosomal abnormalities, which can include missing, extra, and malformed structures, or interchanged segments, are often correlated with MDS diagnoses. However, abnormalities on the same chromosome can result in different prognoses. Having a predicted prognosis for specific conditions can help physicians prescribe effective treatments accordingly.

Deletion 5q and monosomy 5 are two specific abnormalities on chromosome 5. Patients with deletion 5q syndrome have a significant deletion in the long arm of chromosome 5. This condition most frequently occurs in young female Low-risk MDS patients who need red blood cell transfusions, have anemia (low red blood cells counts), and have normal or average platelet counts. In the condition known as monosomy 5, patients lack one entire chromosome 5. Abnormalities are found on chromosome 5 in 20 percent of all MDS patients.

This study evaluated the records of 2,743 patients diagnosed with MDS and referred to the M.D. Anderson Cancer Center records from 1966 to 2009. Eighteen percent of all patients had some type of chromosomal abnormality, while 10 percent had deletion 5q syndrome and 8 percent had monosomy 5. Regardless of previous treatment, survival was measured from the time patients were referred to the cancer center.

Table 1. Median Survival Times for Different Combinations of Chromosome 5 Abnormalities

This study demonstrated that there are different prognoses even among patients who have abnormalities on chromosome 5. In addition, results showed that median survival progressively worsened with increased numbers of additional chromosomal abnormalities (Table 1).

Researchers concluded that those with deletion 5q generally had lower-risk MDS than those with monosomy 5, and that they should not be treated as one group.

For more information, please see the related article in the journal Cancer (abstract).