The ABC building in the Brisbane suburb of Toowong -- subject of a December 2006 post -- has been officially vacated following an investigation that turned up a cancer cluster among female employees.

Over the past 11 years, 10 women from this one building have been diagnosed with breast cancer. Eight of the women worked in the ABC newsroom, and most had been there for more than five years. The breast cancer risk for these women was six times higher than for the general population of women in the area. And while the investigation continues and clues are beginning to connect, the big question -- Why? -- has still not been answered.

It has been determined it is highly unlikely the increase in breast cancer was caused by exposure to radio frequency, low frequency electromagnetic radiation, or chemical contamination. According to experts, had any of these factors been at play, there would have been a rise in cancer among male employees as well as female employees. Therefore, it appears something specific to women has caused this cluster.

Perhaps clues will emerge from an analysis of lifestyle influences -- like smoking, diet, and alcohol and medication use -- and already women have answered questions pertaining to body weight, height, level of physical activity, and reproductive history.

One common theme among women is the use of oral contraceptives for periods varying from two to 18 years. Other interesting findings include the average number of babies born to the women -- 1.6 -- and the breastfeeding practices of the women -- each woman with a child breastfed for an average of 2.3 to 12 months -- and the educational background of the group -- of the 10 women, six have college degrees.

Experts says these are important factors. Early puberty, late menopause, lack of breastfeeding, use of oral contraceptives, and the trend of older mothers having fewer babies all can influence breast cancer risk. And so can level of education. Research shows increased rates of breast cancer in women with white collar jobs -- which is related to socioeconomic status and late childbearing.

Everything is important really -- because as breast cancer rates continue to skyrocket, all possible reasons need to be considered.

One in eight women in Australia will be diagnosed with breast cancer before the age of 85. About 13,261 women were diagnosed with breast cancer in 2006. And it is predicted that 14,818 will be diagnosed in 2011.