Follow-Up Study of People Treated for Scoliosis
Condition: Breast and Other Cancer Incidence and Mortality; All Cause Mortality; Circulatory Disease Mortality; Respiratory Disease Mortality
MeSH terms: Scoliosis; Respiratory Tract Diseases; Respiration Disorders
Study type: Observational

Summary: 
      Background:

      Scoliosis is a curving of the spine. It usually happens in girls when they are children and
      teens. Doctors often use x-rays to diagnose it. The x-rays give low radiation. This may
      increase the risk that those young women get cancer later in life. Researchers want to learn
      more about this risk. They will look data that has already been collected.

      Objectives:

      To study cancer risks of repeated low radiation from x-rays for scoliosis. Also, to study
      death risks related to certain scoliosis patient characteristics. These include causes, kinds
      of curvature, and kinds of treatment.

      Eligibility:

      Medical records of women from past scoliosis studies.

      Design:

      This U.S. Scoliosis Cohort includes more than 5,000 women who were diagnosed between 1912 and
      1965.

      Data were collected on these women in the 1980s and 1990s. These came from medical records,
      radiology log books, and x-ray films. Researchers found out where participants were,
      including if they were dead. Some women were given a follow-up questionnaire.

      Researchers want to find out where participants are today. They want to identify new deaths
      of participants. They want to find out their causes of death. This data will be added to
      other databases.
    

Detailed description: 
      U.S. Scoliosis Cohort includes 5,573 female spinal deformity (93% scoliosis) patients
      diagnosed in any of 14 medical centers in the U.S. during 1912-1965. The primary objective of
      this study is to evaluate site-specific cancer risks associated with repeated low-dose
      radiation exposures from diagnostic x-rays. A secondary objective is to evaluate late
      mortality risks associated with patient characteristics, such as etiology, degree and type of
      curvature, and type of treatment. The current proposal is to extend mortality follow-up by 10
      years. All patients not known to be deceased will be submitted to the National Death Index
      Plus to identify new deaths and obtain causes of death.

      A feasibility study was conducted in four medical centers in the Minneapolis-St. Paul,
      Minnesota area during 1983-1987. The primary goals of the feasibility study were to ascertain
      if an adequate number of patients meeting the study criteria could be identified and located,
      medical and radiography records were available and substantially complete, organspecific
      radiation doses could be estimated from the available data and were large enough to warrant
      further study, and a reasonable percentage of patients would complete a follow-up
      questionnaire. The feasibility study was successful in meeting all goals. Enrolled for study
      were 1,030 female patients with spinal deformities diagnosed during 1922-1965. Medical
      records were abstracted, individual x-ray films were reviewed, patients were located, and
      follow-up questionnaire was administered to identify incident cancers. Eleven breast cancers
      were reported. Scoliosis patients had an 80% higher breast cancer risk compared to women in
      the general population and, based on internal cohort analyses, breast cancer risk increased
      with increasing number of x-rays and with estimated radiation dose to the breast.

      An expanded study was conducted during 1988-1993. The main goals of the expanded study were
      to enlist the collaboration of suitable additional medical centers where large numbers of
      spinal deformity patients were treated before 1966, abstract data from medical and radiology
      records, trace patients for vital status and current location, obtain information on incident
      cancers and cancer risk factors by questionnaire, medically validate reported cancers, and
      determine causes of death for decedents. Another 4,543 patients diagnosed during 1912-1965
      were enrolled from ten hospitals, bringing the total study population to 5,573 patients.
      Compared to women in the general population, spinal deformity patients had statistically
      significantly higher risks of dying from breast cancer, and for both incidence and mortality,
      breast cancer risk increased with increasing diagnostic radiation exposure to the breast.
      Patients also have elevated risks for mortality from all causes, circulatory, respiratory,
      nervous system, musculoskeletal, digestive, and infectious & parasitic diseases, primarily
      related to degree of spinal curvature. Additional mortality follow-up will enable more
      definitive assessments of cancer and other disease risks with radiation and other factors in
      these patients.
    

Observational model: Cohort
Time perspective: Prospective
Keywords: Mortality; Radiation; Spine deformities