Ghent · Canadian journal of surgery. Journal canadien de chirurgie 1993 · multi-study report including uncontrolled series, crossover trial, and double-blind controlled trial · n=56 in double-blind trial; over 1,300 across all series

Iodine replacement in fibrocystic disease of the breast.

Cited 101 times in the scientific literature.

Level 2 - randomized trial

Multi-study report including a prospective double-blind controlled trial (Study 3)

PubMed 8221402 · record verified 2026-08-29

What was done

The authors reviewed three clinical studies conducted since 1975 at university-affiliated breast clinics to assess response to iodine replacement in fibrocystic breast disease. Study 1 was an uncontrolled study of sodium iodide (n = 233, treated for 2 years) and protein-bound iodide (n = 588, treated for 5 years). Study 2 was a prospective controlled crossover study where 145 patients with persistent symptoms on protein-bound iodide were switched to molecular iodine (0.08 mg/kg), alongside 108 volunteers initiated directly on molecular iodine (expanding to 1,365 volunteers by 1989). Study 3 was a prospective double-blind controlled trial comparing molecular iodine (0.07 to 0.09 mg/kg body weight, n = 23) against a placebo mixture of brown vegetable dye and quinine (n = 33). Outcomes assessed were freedom from pain (subjective), resolution of fibrosis (objective), and, in Study 3, pre- and post-treatment mammography and serum T3, T4, and TSH levels.

What was found

In Study 1, clinical improvement occurred in 70% of subjects on sodium iodide (with a high side-effect rate) and in 40% on protein-bound iodide. In Study 2, 74% of crossover patients showed clinical improvement, and 72% of patients treated initially with molecular iodine showed objective improvement. In Study 3, 65% of the molecular iodine group showed both subjective and objective improvement, compared to a 33% subjective placebo effect and a 3% objective deterioration rate in the control group. Molecular iodine was reported as nonthyrotropic.

Why it matters

This paper suggests that molecular iodine is more effective and better tolerated than iodide salts for reducing pain and objective fibrotic changes in fibrocystic breast disease.

Limits

The randomized double-blind component (Study 3) had a small sample size (n = 56 total) and did not report statistical significance values or confidence intervals in the abstract. Studies 1 and 2 were largely uncontrolled or open-label, introducing substantial risk of placebo effect and reporting bias. Specific adverse event rates and mammographic scoring details were not reported in the abstract.

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