Miss Keaton couldn't find any cases of breast cancer among Canadian natives while traveling for 15 years.
April 15, 1957
Miss Mildred H. Keaton Letter
Mrs. Greist, who herself had ceased northern nursing in 1936, advised me to get in touch with a nurse whom the government had sent to help take over the Farthest North Hospital's work when it was transferred by the Presbyterian Church to the Department of the Interior. Mrs. Greist had been deeply impressed with Miss Mildred H. Keaton, both as to her professional training and as to her long and varied experience as a dog team and airplane nurse who was thoroughly familiar with the native situation at the western end of northern Alaska (at the Kotzebue Government hospital, just east of Bering Strait and just north of the Arctic Circle). From there eastward, Miss Keaton had again and again traversed a thousand miles of coast beyond Barrow to the Canadian border.
Miss Keaton replied to my letter on April 15, 1957, from her new post at the White Pass and Yukon Route Hospital, Skagway, Alaska:
“Regarding the absence of cancer from the pre-white Eskimos of arctic Alaska, it has ever been a source of wonder to me that during the fifteen years when I was a field nurse in the Kotzebue and Barrow districts, going east of Barrow to Demarcation Point [on the Canadian boundary], among the more primitive Eskimos, only once did I come in contact with a diagnosed case of cancer ...” (In later correspondence Miss Keaton said this lone case seen by herself was in the middle 1930's, thus two or three years after the above Greist autopsy and cancer identification at Barrow.)
“We field nurses have often wondered why the women did not have breast cancer, due to the way they carried their babies on their backs with a strong leather or reindeer skin belt fastened tightly around their chest ... the pressure on the mammary glands of the breasts must have been severe.
“The late Dr. Ray Edward Smith was hospital physician in Kotzebue for some 16 years ... [serving] a population of native people totaling about three thousand coming to Kotzebue Hospital. He once told me he had always been most pleasantly surprised at the absence of cancer of any kind among these people.”