Interobserver agreement for assessing invasion in stage 1A vulvar squamous cell carcinoma.

Invasive squamous cell carcinoma of the vulva with ≤1 mm stromal invasion is classified as stage 1A. Cancer staging systems state that the depth of invasion should be measured from the epithelial-stromal junction of the adjacent most superficial dermal papilla to the deepest point of the invasive tumor. Measurement of the depth of invasion guides patient management. Even though this measurement is critical, no studies have reported the reliability among pathologists for determining the cutoff point of ≤1 mm stromal invasion in vulvar cancer. We assessed agreement among pathologists for determining whether a vulvar tumor is invasive, for the depth of invasion, and for tumor thickness. Forty-five cases of vulvar squamous cell carcinoma with a depth of invasion of ≤5 mm were chosen. Eleven gynecologic pathologists independently reviewed the slides and, for a subset of cases, pictorially recorded measurements on photographs. The number of cases that were reported as invasive by the 11 pathologists ranged from 21 to 44. The number of cases that were reported as showing a depth of invasion of ≤1 mm ranged from 7 to 27. Eight pathologists provided measurements for all lesions reported as invasive, the remaining 3 pathologists stated that they were unable to measure 2, 7, and 16 lesions, respectively. Mean κ for diagnosing vulvar carcinoma as invasive was 0.24 and for measuring the depth of invasion and thickness was 0.51 and 0.49, respectively. There was only fair agreement in determining whether the lesion was invasive. In cases in which pathologists agreed upon the diagnosis of invasion, agreement on depth was moderate. When using the recommended cancer staging method, interpretation of the location of the most superficial dermal papilla varied among pathologists. Measuring thickness did not improve agreement. This is the first study that has assessed the reliability of the diagnosis of invasion in vulvar cancer among gynecologic pathologists, the interobserver agreement for reporting the critical 1 mm threshold of depth of stromal invasion, and the way in which the International Federation of Gynecology and Obstetrics method is used by pathologists.

The role of alternative oxidase in modulating carbon use efficiency and growth during macronutrient stress in tobacco cells.

When wild-type (wt) tobacco (Nicotiana tabacum cv. Petit Havana SR1) cells are grown under macronutrient (P or N) limitation, they induce large amounts of alternative oxidase (AOX), which constitutes a non-energy-conserving branch of the respiratory electron transport chain. To investigate the significance of AOX induction, wt cells were compared with transgenic (AS8) cells lacking AOX. Under nutrient limitation, growth of wt cell cultures was dramatically reduced and carbon use efficiency (g cell dry weight gain g(-1) sugar consumed) decreased by 42-63%. However, the growth of AS8 was only moderately reduced by the nutrient deficiencies and carbon use efficiency values remained the same as under nutrient-sufficient conditions. As a result, the nutrient limitations more severely compromised the tissue nutrient status (P or N) of AS8 than wt cells. Northern analyses and a comparison of the mitochondrial protein profiles of wt and AS8 cells indicated that the lack of AOX in AS8 under P limitation was associated with increased levels of proteins commonly associated with oxidative stress and/or stress injury. Also, the level of electron transport chain components was consistently reduced in AS8 while tricarboxylic acid cycle enzymes did not show a universal trend in abundance in comparison to the wt. Alternatively, the lack of AOX in AS8 cells under N limitation resulted in enhanced carbohydrate accumulation. It is concluded that AOX respiration provides an important general mechanism by which plant cells can modulate their growth in response to nutrient availability and that AOX also has nutrient-specific roles in maintaining cellular redox and carbon balance.