ABSTRACT
Background: Metastasis of the lymph node is one of the most significant prognostic factors for breast cancer (BC). Aim: To predict positivity of the lymph node in BC patients with help of USG and USG-guided FNAC and thus to prevent unnecessary morbidity. Methods: 50 patients of incisional/true cut biopsy-proven BC patients were included. All were subjected to mammography, USG and FNAC of the lump breast. USG-guided FNAC of the axillary lymph node was done in 25 of these patients. These findings were assessed by histological examination following dissection of the axillary lymph node. Results: Axillary lymph node (ALN) metastasis was present in 42 patients on histopathology; 21 patients suspicious of malignancy on preoperative USG were confirmed by HPE. Out of 88 confirmed lymph nodes evaluated on ultrasonography, 4 were benign, 18 were indeterminate and 66 were suspicious. The most promising features were tumour length/depth ratio of <1.5 in 81, absent fatty hilum in 73% and hypoechoic cortex in 74%. Assessment of axilla with USG had a sensitivity of 50%, a specificity of 100%, a PPV of 100%, an NPV of 27.59% and a diagnostic accuracy of 58%. Preoperative USG-guided FNAC had a sensitivity of 91.67%, a specificity of 100%, a PPV of 100%, an NPV of 33.33% and a diagnostic accuracy of 92%. Conclusion: USG can detect non-palpable axillary lymph nodes and FNAC can increase the sensitivity and specificity of this technique, which makes this procedure very promising in detecting axillary metastases in BC patients.
ABSTRACT
The cytoplasmic male sterile line system comprising CRMS 32A and its maintainer line CRMS 32B is a popular choice for the development of new hybrids in India as CRMS 32A, having Kalinga 1 cytoplasm (other than WA), is a viable alternative to WA cytoplasm. However, both lines are susceptible to bacterial blight (BB), a major disease on rice. As enhancement of host plant resistance is the most effective and economical strategy to control this disease, four resistance genes (Xa4, xa5, xa13, and Xa21) were transferred from a BB pyramid line of IR64, into the A and B lines using a marker-assisted backcrossing (MAB) breeding strategy. During the transfer of genes into CRMS 32B, foreground selection was applied using markers associated with the genes, and plants having resistance alleles of the donor, are selected. Selection for morphological and quality traits was practiced to select plants similar to the recurrent parent. The four gene and three gene pyramid lines exhibited high levels of resistance against the BB pathogen when challenged with eight virulent isolates. Using genome wide based SSR markers for background selection, pyramids having >95% of the recurrent parent genome were identified. With CRMS 32B gene pyramid as donor, the four resistance genes were transferred into the A line through repeated backcrosses and the A line pyramids also exhibited high level of resistance against BB. Through a combination of selection at phenotypic and molecular levels, four BB resistance genes were successfully introduced into two parental lines (CRMS 32 B and A) of Rajalaxmi, an elite popular hybrid. The pyramided B lines did exhibit high levels of resistance against BB. Selection for morphological and quality traits and background selection hastened the recovery of the recurrent parent genome in the recombinants. Through repeated backcrosses, all the four resistance genes were transferred to CRMS 32A and test crosses suggest that the maintenance ability of the improved CRMS 32B lines is intact. These improved maintainer and CMS lines can directly be used in hybrid rice breeding and the new hybrids can play an important role in sustainable rice production in India.
