THE possible existence of a relationship between thyroid activity and both the incidence and progress of breast cancer has been the subject of considerable discussion over a number of years. We reviewed the literature in our paper of 1961, and described the early stages of an experimental approach we were making in an attempt to answer the question (Sicher and Waterhouse, 1961 More than one type of relationship between thyroid function and breast cancer has been considered in the recent literature, and it is not always clear what is under investigation in a particular study. The hypothesis that hyperfunction of the thyroid gland is associated with a reduced incidence of breast cancer is supported by Humphrey and Swerdlow (1964) who found no case of breast cancer among 196 patients with hyperthyroidism followed for 12 years. Stoll (1962), however, cannot support the hypothesis from his study of 150 cases of breast cancer. Capelli and Margottini (1964) failed to detect a decrease in thyroid function among patients with breast cancer. Humphrey and Swerdlow (1964) found, among cases of breast cancer having a history of hyperthyroidism, both a higher 5-year survival rate and a lower incidence of local recurrences than among the remainder of their cases of the disease.The last finding mentioned above seems in conflict with that of Edelstyn, Lyons and Welbourn (1958) that breast cancer patients with only local extensions of growth had consistently higher indices of thyroid activity than patients in whom blood-borne spread had occurred. Reeve et al. (1961) reanalysed the data of Edelstyn et al. (1958) making certain plausible assumptions, and arrived at the same conclusions, although in a study of their own, using groups of patients similar to those of Edelstyn et al., they could show no difference in levels of thyroid activity between patients with local disease or with blood-borne metastases.Similar hypotheses have formed the basis of treatment in cases of breast cancer. Stoll (1962) in a series of 12 advanced cases treated with a combination of oestrogen and tri-iodothyronine (T3) could find no evidence for any regression ascribable specifically to T3. Emery and Trotter (1963) used T3 in a controlled study of 54 advanced cases without finding evidence of any noticeable effect on the prognosis. Lyons and Edelstyn (1965) used desiccated thyroid extract and later thyroxine in comparison with a control series and again could find no evidence of prognostic value in the treatment. They did find however an increased incidence

THE direct or indirect influence of certain hormones, e.g. stilboestrol and testosterone, on the aetiology of malignancy has been well recognised for many years and has formed the basis of their extensive use in the management of this disease, particularly in attempting its control in advanced stages. Some of the cancers of breast and of prostate are good examples of tumours which are hormone dependent. But the role that the thyroid hormone plays is still uncertain. Beatson was the first, in 1896, to treat advanced carcinoma of breast with thyroid extract in addition to oophorectomy. Only in the last decade or so the result of a good deal of experimental work and clinical observation has been to suggest that thyroid secretion plays an important part in the evolution of cancer, particularly of the genitalia and the breast. Loeser (1954) states that the incidence of female breast carcinoma is far lower in allergic and hyperthyroid conditions than in hypothyroid women or after thyroidectomy. In his view, it is the low histamine content of the cells of hypothyroid women which increases the tendency to cancer formation. Spencer (1954), discussing iodine availability in cancer incidence, doubts whether a low metabolic rate or insufficiency of thyroid substance can be considered as a primary cause of cancer. He suggests, rather more vaguely, " that thyroid function (or dysfunction) may be associated with the susceptibility or immunity to cancer ". Sommers (1955), after examining autopsies of breast cancer cases and of about an equal number of adult women without cancer, found hyperplastic modification in one or more endocrine glands and their target organs. A noticeable exception was the thyroid gland, in which atrophy occurred more commonly with than without breast cancer. The thyroid atrophy was independent of the body weight. Dargent and Mayer (1955), surveying 71 cases of cancer of various sites, have attempted to demonstrate that thyroid secretion has a definite influence on the evolution of cancer, and warn that surgical treatment of goitre in a case of established malignancy should not be undertaken lightly. Dessaive (1956) in both his experimental work and clinical observations comes to a similar conclusion. From his study of 13,261 cancers seen in Liege it appears that simple thyroid conditions, particularly goitre, constitute a favourable element in the formation of cancer. The effect was found in women much more often than in men, and was especially noticeable in breast carcinoma. He also found that cancers which develop against a background of thyroid deficiency have a worse prognosis, and recommends full investigation before undertaking surgical or other treatment for simple thyroid disorder, in order to exclude the presence of a cancer which at -that time may be

Factors predisposing to this injury are irreducibility of the hernia, distension of the bowel, and nipping of the bowel against the unyielding surface of the pubic bone. A truss may therefore be a source of danger if it does not completely control the hernia and if the patient sustains an injury which presses the truss and, in tum, the bowel back against the pubis.The following case shows that rupture of the bowel may occur in these circumstances and may lead to a fatal result. CASE HISTORYA man aged 76 had worn a truss over a right oblique inguinal hernia for 30 years. On April 4, 1947, he tripped and fell forward on his face. Immediately after the fall he felt a dull constant pain in the hernia, which had come down. He therefore reduced the hernia without difficulty, although a small lump remained. Severe epigastric pain soon began; at first this was made worse by movement and relieved by lying down, but within half an hour of the accident it appeared to assume a colicky nature, causing the patient to roll in agony. He vomited twice and went to bed. During the night the pain gradually subsided, but vomiting was repeated three or four times. The next day he experienced stabbing pains on movement, and when he coughed there was pain in the hernia. Vomiting continued and his doctor attempted, without success, to reduce the lump in the right inguinal region.On admission to hospital 30 hours after his fall the patient complained of generalized abdominal pain, which was constant and was made worse by movement. His bowels had not functioned since the accident.On examination he was very short of breath and had a constant cough with white mucous expectoration. COMMENTThere is no direct proof that the ruptured loop of ileum occupied the hernial sac at the time of injury. On the other hand, the initial pain was felt in the hernia and abdominal symptoms did not supervene until after its reduction. These facts, together with the bruised condition of the sac as seen at operation, make it highly probable that rupture took place in the sac. It is suggested that the bowel was nipped between the head of the truss and the pubic bone.I am indebted to Dr. J. Thomson, medical superintendent of Dunedin Hospital, and to Professor Gordon Bell for permission to publish these notes.

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